Technical Abstract: Cowpea or Southernpea [Vigna unguiculata (L.) Walp.] is an important legume crop used as a feed for livestock, as a green vegetable and for consumption of its dry beans which provide 22-25% protein. The crop is very sensitive to alkaline soil conditions. When grown at a soil pH of 7.5 or higher, cowpea develops severe leaf chlorosis caused by deficiencies of Fe, Zn and Mn resulting in stunted plant growth and yield reduction. We evaluated in replicated field experiments at St. Croix, USVI and Miami, FL, four plant introductions (PIs) and one commercial cultivar some of which have shown some tolerance to alkaline soils in unreplicated, seed regeneration plots of the U.S. cowpea collection. At both locations, genotype PI 582702 had significantly higher seed protein concentration, averaging 28%. Alkaline soil conditions at St. Croix were severe resulting in average yield of genotypes at this location being significantly lower and 69% less than that in Florida. Nevertheless, some genotypes performed well at both locations. For example, PI 582605 had significantly higher yield in Florida whereas in St. Croix PI’s 582605, 582674 and 582702 were the highest yielders. These genotypes may serve as an alternative to growers or home gardeners wishing to establish a legume crop in areas where agricultural production is severely restricted by high soil alkalinity.