Eight parental lines of diverse origin of tomato (Solanum lycopersicum L.) were crossed in 8 × 8 diallel mating design excluding reciprocals. The 28 F1 hybrids along with their parents and one standard check (H-86) were evaluated in a randomized block design with three replications during seasons of rabi 2011-12, 2012-13 and 2013-14. In the present study, revealed that heterosis over better parent, mid parent, standard check and inbreeding depression was observed for all the traits under studies. Highly significant heterosis was observed for days to first flowering (-13.49, -13.52 and -12.28%), number of flowers per cluster (17.90, 22.11 and 24.27%), days to first harvest (-8.01, -11.04 and -9.76%), number of fruit per cluster (39.17, 42.71 and 20.71%), fruit diameter (19.93, 31.43 and 13.27%), fruit length (19.29, 22.34 and 13.35%), Average fruit weight (18.88, 19.41 and 7.80%), number of fruits per plant (25.86, 46.69 and 41.87%) and yield per plant (58.61, 75.61 and 56.33%) over the better, mid and standard parents, respectively along with considerable inbreeding depression. Most promising cross Pant T-3 × H-24 showed highly significant positive heterosis over better parent for yield per plant
