This study was conducted to determine the effects of restricted light on broiler performance and carcass parameters. Day-old broiler chicks were placed (70 chicks/pen) in each 9 floor pens which were in three different rooms in the poultry house, thus giving us three replicates for each lighting teratment. In the first three days, lighting schedules was 23 h light (L): 1 h dark (D) for all pens. Then three pens were randomly assigned to each of the three leihting treatmens: 1. Group (control): 23L:1D, 2. Group: natural day light from days 4 to 35 and 23L: 1D from days 36 to 40, 3. Group: 23L:1D from days 1 to 21 and 12L: 11D:1L (one hour light at midnight) from days 22 to 40.