A study was undertaken to evaluate the magnitude of heterosis, mean performance and combining ability variance and effects of ten lines, six testers and their 60 crosses in line × tester design in sesame for seed yield and component traits. The F1s along with parents were evaluated in RBD with two replications at Mandor, Jodhpur during kharif 2010. Analysis of variance indicated significant differences among genotypes for all the characters showing variability for all the characters studied. Mean sum of squares due to parents vs. hybrids were significant for all the characters indicating presence of heterosis. The estimates of 2gca variance for days to 50% flowering, maturity, height up to 1st capsule and 2sca variances for all the characters were significant indicating the importance of both additive and non-additive gene actions in the inheritance. Sesame lines RT-356, RT-358 and RMT-332 were found to be good general combiners for majority of characters. The maximum heterobeltiosis percentage was for seed yield plant-1 followed by number of productive capsules on main stem, 1st capsule bearing height and number of productive capsules plant-1 and least was for days to maturity and days to flowering which is important for developing early maturing hybrids with high seed yield. Hybrid combinations RT-358 × MT-1-07, RT-351 × HT-9316, RT-351 × CST-2001-9 and RT-358 × LT-8 showed high per se performance with high heterosis and sca effects for seed yield plant-1 and component characters.