This note shows the results of the "Clean Air Initiative in Sub-Saharan African Cities," a study to evaluate air pollution launched and coordinated by the World Bank. The following items are addressed: (i) estimation of the present global level of air pollution in Cotonou; (ii) determination of transportation's role; (iii) evaluation of the risk to human health and estimation of resulting expenses; (iv) examination of foreseeable future pollution evaluation of results of measures likely to be taken to reduce pollution and (v) proposal of a strategy for the implementation of these measures.