The field experiment was conducted at Regional Horticultural Research and Extension Centre (RHREC), Dharwad. Forty five hybrids derived from 15 lines and three testers were evaluated through RCBD design and analysed by line x tester analysis in order to estimate heterosis for growth, earliness, yield and quality parameters in tomato. The magnitude of heterosis over the commercial check (Arka Rakshak) was highly desirable in positive direction and it ranged from 3.07 to 55.72 per cent for plant height at 90 DAT, -38.31 to 17.41 per cent for number of primary branches per plant at 90 DAT, -55.73 to 7.17 per cent for days to flower initiation, -13.97 to 28.25 per cent for days to fifty per cent flowering, -14.23 to 9.30 per cent for days to first fruit harvest for earliness, -64.58 to 70.98 per cent for average fruit weight, -17.07 to 60.06 per cent for number of fruits per plant, -67.29 to 9.74 per cent for yield per plant, -67.32 to 9.76 per cent for yield per hectare, 7.54 to 79.47 per cent for number of locules per fruits, -17.23 to 121.01 per cent for total soluble solids content of fruit, -30.15 to 0.84 per cent for pericarp thickness, -3.53 to 41.62 per cent for fruit length, -28.66 to 21.23 per cent for fruit girth and -3.40 to 36.60 per cent for fruit colour. The hybrid UHSB-20 x UHSB-32 was the best hybrid selected for yield per hectare as it exhibited maximum standard heterosis of 9.76 per cent and its estimated total yield was 441.35 q per hectare as compared to 402.12 q per hectare of the commercial check (Arka Rakshak) in this experiment. The second best hybrid was UHSB-17 x UHSB-33 and its estimated yield per hectare was 435.46 q with 8.29 per cent standard heterosis.