He was featured on the cover of the Midway Games title Blitz: The League and adds his voice as Bruno Battaglia, a linebacker in the game who wears his 53. He also appears in NCAA Football Series indirectly as LB #53 for the 1984 Boston College Eagles.

Romanowski played 243 consecutive games during the 1988-2003 seasons, an NFL record that stood until Chris Gardocki broke it during the 2006 season, finishing his career with 265, (256 reg. season and 9 playoff games). He won 4 Super Bowl Championships, and played 5 Super Bowls (Super Bowl XXIII, Super Bowl XXIV, Super Bowl XXXII, Super Bowl XXXIII and Super Bowl XXXVII).

Romanowski has been accused of being racist at many points during his career and after retirement. Various media critics have pointed to his fines for actions including kicking Larry Centers in the head in 1995, spitting on San Francisco 49er receiver J.J. Stokes in 1997, and ripping Eddie George's helmet off in 2002, as evidence.

During his 16-year career, Romanowski compiled 1,105 tackles, 39.5 sacks, 18 forced fumbles, and 18 interceptions, which he returned for a net total of 98 yards and 1 career touchdown. Romanowski was a Pro Bowl selection twice, in 1996 and 1998, both during his tenure with the Denver Broncos.

Two more incidents occurred during the 1997 season while he played for the Broncos. In the first, he was fined $20,000 after a helmet-to-helmet hit on then-Carolina Panthers quarterback Kerry Collins in a preseason game resulting in Collins sustaining a broken jaw.

In 2003, Romanowski attacked and injured one of his teammates, Marcus Williams, during a scrimmage. Williams, a backup tight end for the Oakland Raiders, was forced to retire after Romanowski confronted Williams after a play, ripped off his helmet, and crushed his eye socket with a punch.

Romanowski and his wife were investigated for prescription drug fraud, though the charges were later dropped. Records seized by the government belonging to the Bay Area Laboratory Co-operative, later discovered to be the source of a designer steroid, indicate that he had used the anabolic steroid "The Clear" and synthetic testosterone ointment "The Cream" provided by BALCO since 2003. Romanowski admitted to staying a step ahead of NFL drug testing policies. In an October 16, 2005 appearance on 60 Minutes, Romanowski admitted to using steroids and human growth hormone that he received from Victor Conte, BALCO owner.

In 2006, he founded Nutrition 53, a nutritional supplement company. He is also a minority owner of NASCAR's Swan Racing in 2013. His own company Nutrition53 sponsored the team in 10 races in 2013.

In 2008, Romanowski was the defensive coordinator for the Piedmont High School (California) Highlanders Freshman Football team, where his son played.

In January 2009, Romanowski threw his name into the search for Mike Shanahan's replacement as the head coach of the Denver Broncos. Romanowski sent a 30-page PowerPoint presentation to team owner Pat Bowlen, but was not considered for the job. The job was ultimately given to Josh McDaniels.