In addition to fronting Soulfly, Cavalera also branched out into other areas not usually associated with heavy metal Musicians. He became a speaker at music conventions, appearing at CMJ's New Music Marathon in New York and Holland's Crossing Border Festival, both in late 1997, and sang a TV commercial for Sprite in Brazil. After recording the first album, Jackson Bandeira returned to Brazil with Nação Zumbi and was replaced by Logan Mader of Machine Head for the live tour that followed. Soulfly played on the 1998 Ozzfest mainstage alongside Ozzy Osbourne, Megadeth, and Tool, and played small club tours around the world with bands such as System of a Down and Snot. After the world tour in support of Soulfly, Logan Mader was replaced by Mikey Doling who had just been displaced by the breakup of Snot.

Cavalera was troubled during the recording of Soulfly's self-titled album, and on the band's website he said that he founded the band "with the idea of combined sounds and spiritual beliefs". As well as leaving Sepultura, one of the world's most renowned thrash/groove metal bands, he had to deal with the death of his stepson and best friend Dana Wells. The self-titled debut album was released in April 1998, and reached number 79 on the Billboard 200.

Soulfly have been described as nu metal, thrash metal, groove metal, and death metal. Soulfly originally played nu metal but then moved away from the nu metal genre after the early 2000s. Soulfly often incorporate elements of world music such as tribal music and Middle Eastern music into their music.

In late 2001, Joe Nunez left Soulfly to join Stripping the Pistol, saying that it was "time for [him] to move on". Roy Mayorga departed from his band Medication to rejoin Soulfly for the recording of their third album. 3 was the first Soulfly album which was produced by Max Cavalera. Other Musicians performing on 3 included Cristian Machado of Ill Niño, and Guitarist Wiley Arnet and Drummer Greg Hall, and Max's stepson Richie Cavalera. The album reached number 46 on the Billboard 200 in that year. After the release of 3 on June 25, 2002, Soulfly toured throughout Europe and North America with bands such as Slayer, In Flames, God Forbid, and Will Haven.

Cavalera recruited a new lineup in October 2003 for the recording of Soulfly's Prophecy album. Joe Nunez returned on drums with New Jersey native Marc Rizzo, formerly of Ill Niño, on guitar and Kentucky native Bobby Burns, formerly of Primer 55, on bass. David Ellefson, formerly of Megadeth at the time, also played bass on several of the album's songs.

Max Cavalera explained on the band's website that he wanted to use different Musicians as part of the group for each album. "This is an approach that I've wanted to do for a while. I never wanted Soulfly to be a band like Metallica, with the same four guys. On every Soulfly album, we've changed the line up and it will probably continue that way. In order to do that, I had to start from the inside out and bring in people who caught my attention, that I had never played with before, and create this." While a member of Sepultura, Cavalera had shown an interest in world music as shown in Roots, featuring elements of the music of Brazil's indigenous peoples. This approach continued on the Prophecy album, with Cavalera traveling to Serbia to record with traditional Musicians. On the song "Moses", he worked with Serbian band Eyesburn, which also features reggae influences from one of his heroes, Bob Marley. Other tracks on the album feature instruments from the Middle Ages, sheepskin bagpipes, and Serbian Gypsies. Danny Marianino and Asha Rabouin returned as guest vocalists on Prophecy, as well, and Max Cavalera produced the album. Prophecy was released on March 30, 2004 and in April of that year had reached a peak of number 82 on the Billboard 200, although it has reached the top 50 of the Australian album charts. Soulfly followed the album release with tours supporting Black Sabbath and Morbid Angel.

In December 2004, as recording was beginning for Soulfly's fifth studio album, the band was rocked by several tragedies that affected the outcome of the album. On December 8, Max's friend Darrell "Dimebag" Abbott was shot to death while playing in Ohio, and on December 10, Cavalera's 8 month old grandson Moses unexpectedly died due to health complications. The following fall, on October 4, 2005, Dark Ages was released. Many critics have described Dark Ages as a return to Cavalera's thrash metal roots of the early Sepultura days; however, the world music influence found on the first four Soulfly albums is still present. In fact, this time, Cavalera traveled to five different countries — Serbia, Turkey, Russia, France, and the United States — in order to record all the sounds that he desired to have on the new album.

The core band on Dark Ages still consisted of Max Cavalera, Marc Rizzo, Joe Nunez, and Bobby Burns, and on this album, Dave Ellefson came back to lend his talents to a couple of tracks, Eyesburn vocalist Coyote sang on "Innerspirit", Stormtroopers of Death vocalist Billy Milano and Russian singer Paul Fillipenko of FAQ screamed on the hardcore influenced "Molotov", and Max's stepson, Ritchie Cavalera from Phoenix-based band Incite, sang on "Staystrong". Soulfly supported Dark Ages on a world tour with various bands such as Deftones, Korn, Throwdown, and Skindred that has stretched through North America, South America, Europe, Russia, and Australia. On August 17, 2006, Soulfly played the 10th Annual D-Low Memorial show with several guest artists including Dave Ellefson and Roy Mayorga, the latter of whom who currently plays with Stone Sour. Most notably, Max was reunited onstage for the first time in 10 years with his brother Igor Cavalera. Max and Igor formed Sepultura together in the early 1980s, but had not played together since Max's departure in 1997. Igor joined the band midway through the set for a jam on the drums and stayed onstage to play the Sepultura classics "Roots Bloody Roots" and "Attitude" on Joe Nunez's drum kit.

In August 2007, Soulfly did a tour that consisted of a mixture of festival and club shows through Europe before playing the 11th Annual D-Low Memorial Show in Tempe, AZ on August 31, 2007. Cavalera Conspiracy also made their debut live performance at the show by opening for Soulfly. One week after performing the show, Soulfly went to Bobby Burns and Tim Lau's newly renovated Porch Studio in Orlando, FL to begin work on their sixth studio album, which Cavalera had begun writing during the summer. After working halfway through recording until September 29, Cavalera halted the session to travel throughout Egypt to record more sounds to integrate into the new songs. In November 2007, Cavalera returned to Orlando to complete tracking and the album was mixed by Andy Sneap in early 2008. The album featured collaborations Dave Peters from Throwdown and David Vincent from Morbid Angel.

Soulfly released their sixth album entitled Conquer on July 29, 2008. Following the release of the album, the band toured the United States with Devastation and Bleed the Sky in the fall, toured Europe in winter of 2009 with Incite, played a small UK and European festivals during the spring and summer of 2009, and went on a fall 2009 U.S. headlining tour with Cattle Decapitation, Prong, and Mutiny Within.

Soulfly entered the Edge of the Earth Studios in Los Angeles, California on November 6, 2009 to begin recording their seventh album with Max Cavalera and Logan Mader both producing. Through a series of streaming web video updates, frontman Max Cavalera revealed on November 13, 2009 that the album would be called Omen and would feature guest appearances by Tommy Victor of Prong and Greg Puciato of The Dillinger Escape Plan. Additionally, the album features performances on drums from Max's sons: Zyon Cavalera on a b-side cover of Sepultura's "Refuse-Resist" and Igor Cavalera (not to be confused with his brother of the same name) on a cover of Excel's "Your Life, My Life". Omen has been released worldwide on May 25, 2010.

On July 18, 2010, Bassist Bobby Burns posted following message on his Twitter profile: "To all the fans... SOULFLY and I have decided to part ways. Stay tuned for my next projects already in the works. Thanks 4 ur support!!!"

On July 1, 2011, Soulfly has announced that the group has recruited former Static-X and current Asesino, and then Prong, and Ministry Bassist Tony Campos into the band, replacing former Bassist Bobby Burns, who left the group in July of last year.

In August 2011, Joe Nunez was replaced by Borknagar Drummer David Kinkade. In September 2011, the band announced they entered the recording studio to make their next album due for an early 2012 release. In late October it was revealed that recording had finished, and Kinkade claimed that the new album is like "Arise on crack". Confirmed guests on the album were Adam Warren of Oceano and Dez Fafara of Coal Chamber and DevilDriver, although Warren pulled out of recording and was replaced by Cattle Decapitation frontman Travis Ryan. In the December 2011 issue of Metal Hammer, Cavalera stated that the main theme of the album will be slavery, with confirmed song titles "Slave", "Chains", "Legions" (a song about the Roman Empire), "Gladiator", "Redemption of Man by God" (featuring Dez Fafara), and "Revengeance" (with Max's 3 sons featuring: Zyon on drums, Richie on vocals and Iggor writing half the guitar riffs). The album was produced by Zeuss with artwork from Marcelo Vasco, who has designed album artwork for bands such as Borknagar, Obituary, and Dimmu Borgir. On December 6, the album title was announced to be Enslaved and has a release date of March 13, 2012. Soulfly performed at the 13th annual Gathering of the Juggalos in Cave-in-Rock, IL August 2012. Throughout 2012, Soulfly have headlined the "Maximum Cavalera Tour", supported by Incite (fronted by Richie Cavalera) and Lody Kong (featuring Igor Cavalera Jr. and Zyon Cavalera). In October 2012 Kinkade announced his retirement from drumming, leaving Soulfly after their show in Bangkok. Max's son Zyon, who performed during the South America tour earlier in the year, will take over drums for the upcoming US tour and for the foreseeable Future.

In April 2013 Max announced Soulfly's intention to record more material after their tour, with Producer Terry Date, and confirmed on May 3 that Zyon would perform drums on the album. In July Max announced that the album would be called Savages. The band released the album on September 30 in the UK, October 1 in the US, and October 4 in Europe. Savages features a number of guest vocalists including Igor Cavalera Jr. of Lody Kong, Jamie Hanks of I Declare War, Neil Fallon of Clutch, and Mitch Harris of Napalm Death.

On December 6, 2014, Max Cavalera said through an interview that he started writing for the tenth Soulfly record. Cavalera and his gang entered the studio on January 3, 2015. On May 1, Bassist Tony Campos announced via his Facebook page that he was leaving Soulfly to join Fear Factory. Archangel, produced by Matt Hyde, was released on August 14, 2015 through Nuclear Blast. They embarked on the "We Sold Our Souls To Metal" tour on September 30, 2015 to promote the album. The tour was accompanied by the bands Soilwork, Decapitated and Shattered Sun. The tour lasted for a 27 show trek ending in Albuquerque, NM on October 30. They played at The Rockbar Theater in San Jose, CA on Dec 12, 2015.

Soulfly incorporates many styles of metal with Brazilian tribal and world music. All of their first six studio albums debuted on the United States Billboard 200, with a peak position at number 32 for their second album, Primitive. Soulfly has been certified gold by the Recording Industry Association of America. The band has gone through numerous line-up changes, with Cavalera being the only constant member. In an interview with Max in 2015, it reveals that the band's name was taken from the song "Headup" by Deftones, a song that Max collaborated on.

In 2017, they toured North America with Cannabis Corpse, Harm's Way, Noisem and Lody Kong. In this tour, they played the Nailbomb album Point Blank in full, bringing Igor Jr. into the band as co-lead vocalist and keyboardist/sampler for the tour. After releasing his latest album with Cavalera Conspiracy, Max revealed his plans to finish writing and recording the next Soulfly album in early 2018, while also declaring his intentions to bring back some of the tribal elements from the band's early days to commemorate 20 years since Soulfly's self-titled debut album.