Heterosis in rice was studied for yield and component traits in 32 hybrids involving 12 parents comprises of 8 lines and 4 testers. Analysis of variance showed significant differences in parents vs crosses for all the characters except thousand grain weight. Greater variability in the parents indicated the possibility of getting higher heterosis in the crosses. The high manifestation of heterosis for grain yield per plant is evident by significant superiority of hybrids over mid parent was ranging from -19.75 to 30.33 % in several crosses. The high heterobeltiosis for yield per plant was observed in the cross ASD 17 x IR 50. This cross had also high heterobeltiosis for days to first flower, plant height, number of productive tillers per plant and number of grains per panicle. Similarly, the cross IR 55408-01 x IR 50 showed superiority over standard variety for grain yield and also showed significant heterosis for almost all the characters. The development of pure lines from segregating population is very important for evolving high yielding varieties. The crosses exhibiting good heterotic expression in F1 are likely to give better segregants in later generations were additive gene effects were high
