Variability in grain yield (GY), aerial biomass (BM) and number of grains m-2 (G M-2) in F6 lines and commercial varieties of barley was studied, and the relationship among these characters in full-irrigation (FI), drought (D) and rain-fed (RF) conditions was determined. Variation in GY, BM and G M-2 among all genotypes, between F6 lines and varieties, and among genotypes of F6 lines and varieties was significant in all the three soil moisture environments. GY, BM and G M-2 in FI were 23, 14 and 21 % greater than the average of the three soil moisture environments; GY, BM and G M-2 in RF were 21, 16 y 24 % lower than this average. F6 lines produced greater GY (380 g m-2), BM (1027 g m-2) and G M-2 (8641) than the commercial varieties (GY=290 g m-2; BM=726 g m-2 y G M-2=7463) in average of the three environments. GY was positive and significantly associated with BM and G M-2; BM and G M-2 were also associated. GY could be improved in either FI, D or RF environments by selecting genotypes with a greater BM and G M-2 or both of them.