After his time in the Army he settled in Indianapolis, Indiana where he picked up the art of telling toasts, which are traditional, black, oral narrative poems acted out in a theatrical manner. During this time, he still maintained his addiction to narcotics.
In 1960, Knight snatched an elderly woman’s purse in order to support his addiction and was sentenced to serve a ten to twenty-five year term in the Indiana State Prison. Enraged by his lengthy prison sentence, which he believed to be unjust and racist in nature, Knight, during his first year of prison became hostile and belligerent in his ways. However, in the following years of incarceration, he turned to books such as The Autobiography of Malcolm X and the poetry of Langston Hughes. Inspired by them, he redirected his embitterment into the writing of poetry so as to liberate his soul. By drawing from his experience in toasting, Knight developed his verse into a transcribed-oral poetry. The poems he had written during his time in prison were so effective that Dudley Randall, a publisher/poet, published Knight’s first volume of verse, which he called Poems from Prison, and hailed Knight as one of the major poets of the New Black Aesthetic.
Upon his release from prison, Knight married poet Sonia Sanchez in 1968. However, as a result of his ongoing narcotics addiction, the marriage did not last long and the couple were divorced two years later in 1970. He married Mary McNally in 1972 and fathered her two adopted children. They settled in Minneapolis, Minnesota until they separated in 1977. He then resided in Memphis, Tennessee where he received Methadone treatments. He later moved back to Indianapolis where he died of lung cancer on March 10th, 1991.
Knight continued to write throughout his post-prison life. Belly Song and Other Poems (1973) dealt with themes of racism and love. Following the publication of this work he received a Guggenheim Fellowship in 1974. Knight believed the poet was a "meddler" or intermediary between the poem and the reader. He elaborated on this concept in his 1980 work Born of a Woman. The Essential Etheridge Knight (1986) is a compilation of Knight's work.
Knight taught at the University of Pittsburgh, the University of Hartford, and Lincoln University, before he was forced to stop working due to illness. He also continued to be known as a charismatic poetry reader.