Increasing air movement over poultry at high ambient temperatures by using ventilation has become an accepted means of reducing environmental heat stress over the last several years. The present study was carried out to evaluate the effect of air velocity and ambient temperature on broiler performance under a constant RH of 58 % and limited the optimum air velocity, ambient temperature and area house section to achieve the best broiler performance. The main experiments were conducted under four air velocities of 1, 1.5, 2.5 and 3m/sec., four ambient temperatures of 28, 30, 32 and 35°C and two area house sections of 12 2.7 and 12 3 m² at 4, 5, 6 weeks of age taking into consideration body weight, feed intake, feed conversion ratio, mortality rate, production efficiency factor (PEF) and specific energy. The obtained data showed that the highest rates of weekly broiler performance where recorded under air velocity of 2.5 m/sec., ambient temperature below 28°C and area house section of  12 2.7 m².