The effect of air velocity on weight gain, feed intake, and feed efficiency was studied in male broiler chickens exposed to a constant temperature of 35 oC, and relative humidity of 60%, and continuous illumination from 4 through 7 wk of age. In two separate trials, air velocity of 0.5, 1.5, 2.0, and 3.0 m/s (Trial 1) and 1.0, 1.5, 2.0, and 2.5 m/s (Trial 2) were used. The fifth week was used for acclimation to the targeted environmental conditions. Weight gain was significantly higher in broilers exposed to air velocity of 1.5 and 2.0 m/s in both trials, which coincided with significantly higher feed intake and feed efficiency. Exposure to the low air velocity (0.5 and 1.0 m/s) resulted in weight gain, feed intake, and feed efficiency that were less than those of broilers exposed to high air velocity (2.5 and 3.0 m/s). In all treatments, broilers developed hyperthermia, but there were not significant differences in body temperature among the birds. It can be concluded that air velocity has a significant effect on broiler performance, the optimal air velocity was found to be 1.5 and 2.0 m/s.