This paper evaluates how Optimality Theory has given phonologists of African languages a new perspective on classic problems like tone shift or spread, vowel harmony, and reduplication. Three case studies are presented: Nguni tone shift, Yoruba vowel harmony, and Bantu verbal reduplication. It is shown that, for each of these problems, OT provides a new perspective, limits the abstractness of the analysis, and defines a factorial typology which provides a framework for comparative analysis. The paper concludes with the reminder that African languages provide a fruitful source of challenges for any theoretical framework.