Japanese Quails were seperated into 3 weight groups depending on hatching weight (1(st) group 5.5-6.2 g, 2(nd) group 6.3-7.0 g and 3(rd) group 7.1-7.8 g). The effect of hatching weight on mean live weight, weight gain, feed consumption and feed conversion during the rearing period was found significant (P < 0.05). The effect of hatching weight on mortality was not significant. Females in each group were placed in cages at the end of the rearing period (5(th) week). The effect of hatching weight on age and weight at sexual maturity was found to be significant (P < 0.01). Mean age of females at sexual maturity was found as 43.6, 42.0 and 41.6 days in the 1(st), 2(nd) and 3(rd) groups, respectively. Sexual maturity weight of females was found as 181.4 +/- 5.12, 194.7 +/- 5.68 and 203.4 +/- 6.94 g, respectively. The highest rate of lay and mean egg weights were obtained with the highest hatch weight group.