This review synthesises evidence on the main types of floods and causes of flooding in urban areas in Africa, and what factors increase flood risk in African cities (and particularly in Nigeria). It draws on lessons learned from Africa and Asia, type of interventions used to manage urban flood risk in developing countries, and how effective these interventions have been in terms of cost-benefit analysis, number of beneficiaries or other metrics relating to value for money. The literature shows that the costs and benefits of interventions vary greatly from one location to another, depending on specific local geographic, economic, and social factors as well as on specific details of project design and implementation. Furthermore, economic evaluation of flood risk management initiatives involves working with limited data, high levels of uncertainty, and assumptions about intangible and indirect benefits and costs.