Before the civil war, conversion to Islam for Igbo men resident in the predominantly Hausa city of Kano in northern Nigeria usually meant becoming Hausa. More recent converts, however, have retained their Igbo identity and created an organisation, the Igbo Muslim Community. Three case studies from the first group detail the process and criteria of becoming Hausa, including immersion in Hausa economic and social networks; three case studies from the second group demonstrate that, while Hausa-centred networks remain important, converts have worked to construct new, Igbo-centred support structures. The watershed in the changing relationship between religious and ethnic affiliation for Igbo converts is the end of the war in 1970 and resultant changes in Igbo perceptions of Muslims, and changes in Igbo community structures.