In 1987, he set up the State of Bengal group in London after a visit to Noakhali, Bangladesh, where he interacted with traditional folk musicians and dancers. Original members of the group included his brother Deedar Zaman (later associated with the Asian Dub Foundation), and MC Mustaq (lead rapper for Fun-Da-Mental). Outside of the State of Bengal project, Zaman also worked with British Asian youth groups, setting up music training workshops.
State of Bengal was a DJ at the influential Anokha club in London' East End during the mid-1990s. His tracks "Flight IC408" and "Chittagong Chill" – written and produced with Matt Mars – were featured on Anokha – Soundz of the Asian Underground compilation, and helped him gain prominence. Singer Björk discovered his work at Anokha; he opened with the homeogenic world tour, and remix her track "Hunter" after hearing the original "Hunter" by State of Bengal in September 1996, thereby signing to the One Little Indian record label. After Anokha, State of Bengal took up residency at the Off Centre club nights. He produced his debut album Visual Audio toured solo and at several international festivals, and did extensive remix work.
After the release of Visual Audio, State of Bengal worked on two significant projects with musicians from Bengal, collaborating with Indian sitar innovator Ananda Shankar, a long-time hero, on the 2000 album Walking Onm and with Baul singer Paban Das Baul on the 2004 album Tana Tani (Push and Pull). In 2007, State of Bengal released his latest album Skip-IJ.