Heterosis for yield and other component characters of 45 F1 hybrids of tomato derived from the crosses between 15 lines and 3 testers through line x tester technique was studied. Maximum and significant heterosis in favourable direction was observed for yield, fruit number, plant height and fruits per cluster. Heterosis was appreciable in all hybrids, but was more in four hybrids viz Sioux x FT-5, S-1001 x Solan Vajr, EC-521041 x FT-5 and S-1001 x EC-15998.