The Bean/Cowpea CRSP has been funding the Institut Sénégalais de Recherches Agricoles (ISRA) since 1982 with the goal of developing improved varieties of cowpea. Cowpea is well suited to Senegalese production zones, and is a relatively inexpensive protein source. It can be eaten as both green pods, which are produced early in the growing season, or as dried seeds when harvested after full maturity. Yields of dry seeds are very low in Senegal, with an average yield around 340 kg/ha. ISRA has been working to develop improved higher-yielding varieties with resistance to drought, pests, and diseases. With this goal in mind, three improved varieties have been produced and extended among Senegalese farmers. A survey was commissioned in order to measure adoption rates for and yield improvements from the three varieties in the main cowpea producing regions of Diourbel, Thiès, and Louga. The sample adoption rate for CRSP varieties was 41.8%, with Louga having significantly higher adoption rates than the other regions. An economic assessment using regional adoption rates and yield improvements resulted in an IRR of 17.9% and an NPV of $78.6M. The benefit stream for the program largely comes from Louga, where the combination of high adoption rates, large yield improvements for improved varieties, and intensive production created benefit streams significant enough to offset costs early in the program life.