A study was conducted to determine the stability of seed yield in 20 sesame (Sesamum indicum L.) cultivars and selections which were grown in replicated trials at three locations in the Central Rainlands of the Sudan in each of three years. Two stability parameters were obtained (1) as the linear regression (b) of an entry mean on an environmental index and (2) the deviations from regression (S2d). Stability was tested with the hypothesis that b = 1.0 and S2 d = 0. The materials studied differed significantly for seed yield and genotype × environment (GE) interactions. Regression coefficients ranged 0.573-1.388 and were statistically close to unity except for UCR 76437 with b - 0.573. Entries with high mean yields generally had regression coefficients exceeding unity and were equal to or better than entries having smaller response even in poor environments. Deviations from regression were significant in nine cultivars/selections. Three (A/1/9 for cultivation in all environments, UCR 75093 for the Agadi area and UCR 76202 for the Abu Naama area) were identified as desirable cultivars/selections and therefore deserving a place in commercial production and future breeding programmes.