Two experiments were carried out to determine the effect of flock age on egg laying pattern, floor laying, egg weight, hatchability, fertility and body weight at hatch. Eggs were collected from 32and 43 wk old Cobb 500 broiler flocks for 6 consecutive days hourly to study egg laying pattern and floor laying (experiment 1). In experiment 2, 2916 eggs from the flock at 32 ,43 and 49 wk old were used to determine the effect of flock age on egg weight, hatchability, fertility and body weight at hatch.