He won a scholarship to Rutgers University-New Brunswick in 1951, but transferred in 1952 to Howard University. His classes in philosophy and religious studies helped lay a foundation for his later writings. He subsequently studied at Columbia University and the New School for Social Research without obtaining a degree.

In 1954, he joined the US Air Force as a gunner, reaching the rank of sergeant. His commanding officer received an anonymous letter accusing Baraka of being a communist. This led to the discovery of Soviet writings in Baraka's possession, his reassignment to gardening duty and subsequently a dishonorable discharge for violation of his oath of duty. He later described his experience in the military as "racist, degrading, and intellectually paralyzing." While he was stationed in Puerto Rico, he worked at the base library, which allowed him ample reading time, and it was here that, inspired by Beat poets back in America, he began to write poetry.

The same year, he moved to Greenwich Village, working initially in a warehouse of music records. His interest in jazz began during this period. At the same time he came in contact with the avant-garde Black Mountain poets and New York School poets. In 1958 he married Hettie Cohen, with whom he had two daughters, Kellie Jones (b. 1959) and Lisa Jones (b.1961). He and Hettie founded Totem Press, which published such Beat poets as Jack Kerouac and Allen Ginsberg. They also jointly founded a quarterly literary magazine, Yugen, which ran for eight issues (1958–62).

In Rain Taxi, Richard Oyama criticized Baraka's militant aesthetic, writing that Baraka's "career came to represent a cautionary tale of the worst 'tendencies' of the 1960s—the alienating rejections, the fanatical self-righteousness, the impulse toward separatism and Stalinist repression versus multi-racial/class coalition-building...In the end, Baraka's work suffered because he preferred ideology over art, forgetting the latter outlasts us all."

His first book of poems, Preface to a Twenty Volume Suicide Note, was published in 1961. Baraka's article "The Myth of a 'Negro Literature'" (1962) stated that "a Negro literature, to be a legitimate product of the Negro experience in America, must get at that experience in exactly the terms America has proposed for it in its most ruthless identity." He also stated in the same work that as an element of American culture, the Negro was entirely misunderstood by Americans. The reason for this misunderstanding and for the lack of black literature of merit was, according to Jones:

In 1963 Baraka (under the name LeRoi Jones) published Blues People: Negro Music in White America, his account of the development of black music from slavery to contemporary jazz. When the work was re-issued in 1999, Baraka wrote in the Introduction that he wished to show that "The music was the score, the actually expressed creative orchestration, reflection of Afro-American life.... That the music was explaining the history as the history was explaining the music. And that both were expressions of and reflections of the people." He argued that though the slaves had brought their musical traditions from Africa, the blues were an expression of what black people became in America: "The way I have come to think about it, blues could not exist if the African captives had not become American captives."

Baraka (under the name LeRoi Jones) wrote an acclaimed, controversial play Dutchman, in which a white woman accosts a black man on the New York subway. The play premiered in 1964 and received the Obie Award for Best American Play in the same year. A film of the play, directed by Anthony Harvey, was released in 1967. The play has been revived several times, including a 2013 production staged in the Russian and Turkish Bathhouse in the East Village, Manhattan.

Baraka's decision to leave Greenwich Village in 1965 was an outgrowth of his response to the debate about the Future of black liberation.

In 1966, Baraka married his second wife, Sylvia Robinson, who later adopted the name Amina Baraka. The two would open a facility in Newark known as Spirit House, a combination playhouse and artists’ residence. In 1967, he lectured at San Francisco State University. The year after, he was arrested in Newark for having allegedly carried an illegal weapon and resisting arrest during the 1967 Newark riots, and was subsequently sentenced to three years in prison. His poem "Black People", published in the Evergreen Review in December 1967, was read by the judge in court, including the memorable phrase: "All the stores will open if you say the magic words. The magic words are: "Up against the wall motherfucker this is a stick up!" Shortly afterward an appeals court reversed the sentence based on his defense by attorney Raymond A. Brown. He later joked that he was charged with holding "two revolvers and two poems".

In 1967, Baraka (still Leroi Jones) visited Maulana Karenga in Los Angeles and became an advocate of his philosophy of Kawaida, a multifaceted, categorized Activist philosophy that produced the "Nguzo Saba," Kwanzaa, and an emphasis on African names. It was at this time that he adopted the name Imamu Amear Baraka. Imamu is a Swahili title for "spiritual leader", derived from the Arabic word Imam (إمام). According to Shaw, he dropped the honorific Imamu and eventually changed Amear (which means "Prince") to Amiri. Baraka means "blessing, in the sense of Divine favor."

Prior to this time, Baraka prided himself on being a forceful advocate of black cultural nationalism; however, by the mid-1970s, he began finding its racial individuality confining. Baraka's separation from the Black Arts Movement began because he saw certain black Writers – capitulationists, as he called them – countering the Black Arts Movement that he created. He believed that the groundbreakers in the Black Arts Movement were doing something that was new, needed, useful, and black, and those who did not want to see a promotion of black expression were "appointed" to the scene to damage the movement.

In 1974, Baraka distanced himself from Black nationalism and converted to Marxism-Leninism and became a supporter of third-world liberation movements.

In 1979, he became a lecturer in the State University of New York at Stony Brook's Africana Studies Department in the College of Arts and Sciences at the behest of faculty member Leslie Owens. Articles about Baraka appeared in the University's print media from Stony Brook Press, Blackworld, and other student campus publications. These articles included an expose about his positions on page one of the inaugural issue of Stony Brook Press on October 25, 1979 discussing his protests "against what he perceived as racism in the Africana Studies Department, as evidenced by a dearth of tenured professors." Shortly thereafter, Baraka took a tenure-track assistant professorship at Stony Brook in 1980 to assist "the struggling Africana Studies Department"; in 1983, he was promoted to associate professor and earned tenure.

In 1980 Baraka published an essay in the Village Voice that was titled Confessions of a Former Anti-Semite. Baraka insisted that a Village Voice Editor entitled it and not himself. In the essay Baraka went over his life history including his marriage to Hettie Cohen who was of Jewish descent. He stated that after the assassination of Malcolm X he found himself thinking "As a Black man married to a white woman, I began to feel estranged from her … How could someone be married to the enemy?" So he divorced Hettie and left her with their two bi-racial daughters. In the essay Baraka went on to say "We also know that much of the vaunted Jewish support of Black civil rights organizations was in order to use them. Jews, finally, are white, and suffer from the same kind of white chauvinism that separates a great many whites from Black struggle. …these Jewish intellectuals have been able to pass over into the Promised Land of American privilege." In the essay he also defended his position against Israel saying "Zionism is a form of racism." Near the end of the essay Baraka stated "Anti-Semitism is as ugly an idea and as deadly as white racism and Zionism …As for my personal trek through the wasteland of anti-Semitism, it was momentary and never completely real. ...I have written only one poem that has definite aspects of anti-Semitism…and I have repudiated it as thoroughly as I can." The poem Baraka referenced was For Tom Postell, Dead Black Poet which contained lines including "...Smile jew. Dance, jew. Tell me you love me, jew. I got something for you... I got the extermination blues, jewboys. I got the hitler syndrome figured...So come for the rent, jewboys...one day, jewboys, we all, even my wig wearing mother gonna put it on you all at once."

During the 1982–83 academic year, Baraka was a visiting professor at Columbia University, where he taught a course entitled "Black Women and Their Fictions." After becoming a full professor of African Studies at Stony Brook in 1985, Baraka took an indefinite visiting appointment in Rutgers University's English department in 1988; over the next two years, he taught a number of courses in African American literature and music. Although Baraka sought a permanent, tenured appointment at the rank of full professor in early 1990 (in part due to the proximity between the University's campus in New Brunswick, New Jersey and his home in Newark), he did not attain the requisite two-thirds majority of the senior faculty in a contentious 9-8 vote that favored his appointment. Baraka would go on to collectively liken the committee to an "Ivy League Goebbels" while also characterizing the senior faculty as "powerful Klansmen," leading to a condemnation from department chair Barry Qualls. Thereafter, Baraka remained nominally affiliated with Stony Brook until his death as professor emeritus of Africana Studies. In 1987, together with Maya Angelou and Toni Morrison, he was a speaker at the commemoration ceremony for James Baldwin.

In 1989 Baraka won an American Book Award for his works as well as a Langston Hughes Award. In 1990 he co-authored the autobiography of Quincy Jones, and 1998 was a supporting actor in Warren Beatty's film Bulworth. In 1996, Baraka contributed to the AIDS benefit album Offbeat: A Red Hot Soundtrip produced by the Red Hot Organization.

Carved in marble, this installation features excerpts from the works of several New Jersey poets (from Walt Whitman, william Carlos Williams, to contemporary poets Robert Pinsky and Renée Ashley) and was part of the renovation and reconstruction of the New Jersey Transit section of the station completed in 2002.

Baraka served as the second Poet Laureate of New Jersey from July 2002 until the position was abolished on July 2, 2003. In response to the attempts to remove Baraka as the state's Poet Laureate, a nine-member advisory board named him the poet laureate of the Newark Public Schools in December 2002.

Baraka ceased being poet laureate when the law became effective. In response to legal action filed by Baraka, the United States Court of Appeals for the Third Circuit ruled that state officials were immune from such suits, and in November 2007 the Supreme Court of the United States refused to hear an appeal of the case.

In 2009, he was again asked about the quote, and placed it in a personal and political perspective:

Amiri Baraka died on January 9, 2014, at Beth Israel Medical Center in Newark, New Jersey, after being hospitalized in the facility's intensive care unit for one month before his death. The cause of death was not reported initially, but it is mentioned that Baraka had a long struggle with diabetes. Later reports indicated that he died from complications after a recent surgery. Baraka's funeral was held at Newark Symphony Hall on January 18, 2014.