The objective of this study was to evaluate the effect of breeding age on reproductive parameters (egg weight, fertility, hatchability and hatch weight) in Japanese · quail (Coturnix cotumixjaponica). A total of 300 eggs, from 3 different breeders (100 each), produced by birds at 5, 10 and 15 months of age were incubated. Hatchability was 68%, 82% and 69% at 5, 10 and 15 months, with fertility rates of 90%, 95% and 92%. Egg (12.29 ± l.64g) and hatch weights (8.22 ± l.84g) were significantly greater (p<0.05) for the 10-month-old birds. A positive correlation between egg weight and hatch weight averages was found for ali three flocks, with r= 0.942 for 10 month, r=0.863 for 5 month and r=0.821 for 15 month old birds. Embryo mortality was greatest at 15 (23%) and 5 (22%) months, compared to 10 months (13%).