Two field experiments were conducted in 2007 and 2008 to evaluate the performance of four cowpea varieties to different densities (0, 5, 20 and 35 m-2) of guinea grass at the Experimental Garden of the Ambrose Alli University, Ekpoma. The experimental design was a 4 x 4 factorial scheme. Weed densities did not significantly (P>0.05) affect plant height at 3, 6 and 9 weeks after planting (WAP) but the varieties did. However, the interaction between weed densities and varieties was not significant throughout the study. Dry matter yield by the different cowpea varieties significantly (P<0.05) decreased with increasing weed densities. There were significant (P<0.05) differences among the varieties in terms of number of days to 50% flowering while interactions between varieties and weed densities were not
significant. Number of pods was significantly (P<0.05) influenced by varying weed densities and varieties. Varying weed densities and varieties significantly influenced cowpea yields.