Scholarship in African economic history has been dominated by a wave of revisionism lately. The degree of African indebtedness, the imperatives of loan repayment, and the long-term implications of ongoing political and economic changes, all make such a revision exigent indeed. Focusing on the Yoruba of southwestern Nigeria, this paper produces new evidence to reinterpret and redefine African precolonial financial institutions. The paper has two main parts. Part 1 focuses on the introduction of cowrie currency into Yorubaland and its impact on social stratification. Part 2 examines ajo, the savings institution, esusu, the rotating savings and credit associations (roscas), and the process of capital formation and accumulation among the Yoruba.