Two experiments were conducted to determine the effect of season and age of hen on reproductive traits in the Rhode Island Red (RIR) and Rhode Island White (RIW) strains of chickens. In the two experiments, data were obtained from two hundred and fifty two (252) hens and twenty eight (28) cocks. The traits measured were fertility, hatchability of all eggs, hatchability of fertile eggs and chick weight at hatching. The percentages of the reproductive traits were transformed on arc sine scale. The mean monthly/seasonal percent fertility, hatchability of all eggs and hatchability of fertile eggs were 87.83% and 85.03%, 71.57% and 71.06%, 81.25% and 84.35% respectively for the RIR and RIW strains. Those obtained on the transformed scale were 69.75% and 67.10%, 58.35% and 58.69%, 64 80% and 67.67% respectively for the RIR and RIW strains. The differences within and between the strains in this experiment for fertility, hatchability of all eggs and of fertile eggs were not significant (P>0.05) with respect to month and season, though S.E and coefficient of variability were slightly higher in the RIW strain than in the RIR strain. The mean percent fertility, hatchability of all eggs and of fertile eggs at different ages were found not to be significantly different in the RIR strain. In the RIW strain, significant age difference was not observed in fertility, however, age of hen was found to have a significant effect (P<0.001) on the hatchability of all eggs and of fertile eggs. A negative and no significant relationship was obtained with Pearson corellation between age and percent fertility, hatchability of all eggs, hatchability of fertile eggs and day old chick weight (ACW). The overall mean percent fertility, hatchability of all eggs and hatchability of fertile eggs over the age group studied (56 - 72) weeks were 80.89% and 89.93%, 43.97% and 53.95%, 49.00% and 57.45% respectively for the RIR and RIW strains on the untransformed scale. The values on the transformed scale were 71.80% and 79.46%, 39.15% and 47.98%, 43.48% and 51.14% respectively for the RIR and RIW strains. The differences between strains in this experiment for fertility, hatchability of all eggs and of fertile eggs were significant (P<0.001). In the two strains, age of hen was found to have a significant effeet(P<0.001) on the average day old chickweight. The over-all average day old chick weight (ACW) over the age group studied was 35.65g for the RIR chickens and 34.97g for the RIW chickens. Difference between the strains for ACW was found to be significant (P<0.01). In the two experiments, fertility percentages obtained for the two strains were generally high and encouraging. Hatchability percentages as expressed to all and fertile eggs on the other hand were higher in experiment 1 (effect of season on fertility and hatchability) and lower in experiment 2 (effect of age of hen on hatchability and chickweight). Failure of fertile eggs to hatch or early embryonic death accounts for the low hatchability percentages obtained for the RIR and RIW strains in experiment 2 rather than infertility. Thus the overall management of the birds on the farm needs to be generally improved.