In order to evaluate water stress tolerance-related traits and their relationships in barley genotypes, as well as identification of drought tolerant genotypes, a field experiment was carried out during 2012-13 and 2013-14 growing seasons in College of Agriculture, Shiraz University, Iran. Seventy four foreign barley genotypes and two Iranian varieties (Reyhan and Nosrat) were evaluated under normal irrigation and water stress (water withheld at flowering stage) conditions according to a split plot experiment based on a randomized complete block design. Correlation analysis indicated that stress tolerance index (STI) was the best criterion for selecting barley drought-tolerant genotypes and significant correlations between number of fertile spikes, spike length, biomass, and seed yield and stress tolerance index were observed. Based on STI, the genotypes number 17, 23, 24, 41, 47, 58, 65, 71 and 72 were proved to be the most tolerant and high-yielding genotypes under both normal and water stress conditions.