The paper argues that the scholarship on democracy in Africa has paid insufficient attention to the nature of opposition parties. It first examines opposition parties in contemporary Africa, studying trends in electoral composition and legislative politics. The paper then links informal and formal institutions, focusing on opposition parties and on the factors that may explain the strength and weaknesses of opposition parties across the region in recent years. The authors suggest a weak or even non-existent relationship between level of democratic institutionalization and the size of opposition parties across the region. Comparative and case analyses of sub-Saharan African elections confirm the weakness of opposition parties in Africa as a striking characteristic of the multi-party systems in the region.