Drought is a common abiotic stress in Ethiopian agriculture. Crop yield is at risk due to drought that happens at various developmental stages of the crop. This experiment evaluated 248 Ethiopian bread wheat genotypes under water stress and non-stress growing conditions. Augmented complete block design with three blocks and eight replicated entries was used. Analysis of variance showed significant diversity among the genotypes in reaction to water stress. The average root and shoot lengths were reduced by 33.4% and 28.8%, respectively, due to water stress. The average fresh biomass per plant was 192 mg for non-stressed and 116 mg for stressed treatments, suffering a 40.5% reduction due to stress. Accessions 8314, 204463, 204454 and 204521 showed the longest roots while accessions 222381, 222405, 222439 and 204586 showed the shortest roots under stress conditions. Drought tolerance indices were calculated based on root length. Geometric mean performance (GMP) index was found helpful in identifying the relatively stable genotypes across the two water regimes. High GMP indices were observed for genotypes 8314, 204521, 231614, and KSN81 which were long rooting genotypes under both stress and non-stress conditions. ANOVA based on region of collection showed that genotypes from Southern Nations Nationalities and Peoples Region had the longest roots. Elevation of origin did not show any significant difference for any of the traits measured. This study demonstrated the presence of large variations for water stress response in the Ethiopian bread wheat germplasm. The identified stress resistant genotypes can be used as potential breeding stocks to develop drought resistant cultivars.