Today, cowpea has remained a rather neglected and underutilized crop in Serbian agriculture. Due to its multipurpose nature, cowpea could be reintroduced into the agriculture of Serbia and other southeast European regions. To get more information about that possibility an experiment was carried out in field conditions under both rainfed (nonirrigated) and irrigated (well-watered) conditions in Novi Sad (45°20' N latitude, 19°51'E longitude, 84 m above sea level) in the years of 2011 and 2012. The experiments were arranged in completely randomized design with three replications. Overhead sprinkler irrigation system was used. Two different genotypes of cowpea (G1 and G2) were studied. To estimate the sensitivity of cowpea to water stress drought tolerance indices were estimated. The plant seed yield of cowpea was significantly higher in irrigation (10.33 g plant-1) than in rainfed (4.35 g plant-1) conditions. Determined drought tolerance indexes revealed that genotype G1 was more tolerant to drought stress than genotype G2. To obtain more information on behavior of these two cowpea genotypes under stress conditions, comprehensive and comparative studies, including new cowpea genotypes should be carried out. Obtained results could be used in breeding programs to make cultivars which will enable this crop to be grown in large area in the region of Serbia.