After Erick Sermon of the seminal group EPMD spotted Redman freestyling in a New York club, Sermon added him to the Hit Squad crew of aspiring MCs (along with K-Solo, Sermon's EPMD, Das EFX and Keith Murray). Redman made his rapping debut on the EPMD songs "Hardcore" and "Brothers on my Jock" off their third album ''Business as Usual'' (Def Jam 1990). Redman's 1992 Def Jam debut Whut? Thee Album broke into the US Top 50 and achieved gold status in the United States. Prominent hip-hop magazine The Source subsequently named Redman the Rap Artist of the Year for 1993.
Redman's solo career continued throughout the remainder of the decade, with each of his albums selling at least half a million copies. His musical style has remained very consistent, rarely deviating from a combination of Redman's unique braggadocios wit and hard, P-funk-influenced beats. In addition to releasing albums under his own name, he is part of the group Def Squad (along with Keith Murray and Erick Sermon) with whom he released the 1998 album ''El Nino'', and also has formed a close partnership with label mate Method Man (of the Wu-Tang Clan) with whom he released the 1999 album ''Blackout!'' He has also collaborated extensively, both with hip hop artists and with artists from other genres; the long list of artists and groups he has worked with includes Wyclef Jean, Snoop Dogg, Scarface, The Offspring, Eminem, Gorillaz, D'Angelo, Me'shell Ndegeocello, 2Pac, Jodeci, Cypress Hill, De La Soul, Tribe Called Quest, KRS One, IAM and Christina Aguilera. Redman arguably had his best-known international mainstream hit with Aguilera, when he featured on her 2002 single "Dirrty".