Omotosho returned to Ibadan to lecture on Arabic studies (1972–76), then moved to the University of Ife to work in drama (1976–88). He became a writer for various magazines (including West Africa) in the 1970s and was well known among Nigeria's literate elites. His major themes include interracial marriage, comic aspects of the Biafran-Nigerian conflict, and the human condition—as exemplified in friendship between the Yoruba and the Igbo and in relationships between children and parents.
His 1988 historical novel about Nigeria, Just Before Dawn (ISBN 9789782460073), was controversial and led Omotosho to leave his native country. After visiting professorships in English at the University of Stirling and the National University of Lesotho and a spell at the Talawa Theatre Company, London, he became a professor of English at the University of the Western Cape in South Africa (1991–2000).From 2001 to 2003 he was a professor in the Drama Department at Stellenbosch University. He also appeared as the “Yebo Gogo man” in television advertisements for Vodacom mobile phones and in 2013, he became a Patron of the Etisalat Prize for Literature. Omotosho is married with three children.
Omotosho grew up during the rising tide of radical nationalism and was enamored by the potential that lay in the future of his country. His fiction ranges widely over the human condition, and themes include intergenerational and interracial relationships. Fela's Choice is an early example of Nigerian detective fiction. However, with the ascent of social and political decay, a few years after independence, he became deeply interested in writing about fiction. Fiction was an avenue that exists apart from the decay of real life and where deep reconstructions about life and ideas come true. It was also an avenue to experiment on social and political ideas for societal change and advancement. Omotosho’s non-fiction is wide-ranging in subject matter.