This trial has been conducted to determine the effect of reducing calcium (Ca) and available phosphorus (AvP) on performance, carcass yield, tibia traits, and jejunum histomorphology in broilers. For this purpose, 480 one-day-old Ross 308 male chicks have been distributed to 4 trial groups with 8 subgroups. During starter period, birds have been fed with recommended or reduced Ca and AvP levels of 66.7 g/kg and 62.5 g/kg, respectively. Calcium and AvP contents of the groups have been as follows: Control, 8.70 g/kg Ca - 4.40 g/kg AvP for grower and 7.80 g/kg Ca - 3.90 g/kg AvP for finisher; LCP1, 8.30 g/kg Ca - 4.20 g/kg AvP for grower and 7.10 g/kg Ca - 3.50 g/kg AvP for finisher; LPC2, 7.90 g/kg Ca - 4.00 g/kg AvP for grower and 6.00 g/kg Ca - 3.00 g/kg AvP for finisher; LPC3, 7.00 g/kg Ca - 3.80 g/kg for grower and 5.00 g/kg Ca - 3.00 g/kg AvP for finisher. Performance parameters have been calculated from the data of each period, and samples have been taken from the slaughtered birds at the final of trial (42nd d) for carcass and tibia traits and jejunum histomorphology. Reducing dietary Ca and AvP did not affect the broiler performance, carcass yield, and mortality. Tibia ash decreased in LCP2 and LCP3 groups (P<0.01). Villus width and villus surface area increased in LCP2 and LCP3. Overall, feeding with a diet 100 g/kg lower than the recommended Ca and AvP did not affect performance in broilers, but improved jejunal development.