The design and operation of broiler house ventilation are directly related to the air inlet characteristics. Air leakage affects the air distribution and mixing inside the houses causing negative effects on the inside air quality and environmental control. A common method of evaluating broiler house tightness is to entirely close the house, turn on a single 1.2m (48-inch) exhaust fan, and record the static pressure. A new procedure to assess broiler house tightness was developed. Fourteen air leakage curves (of the form Q = k(ΔP) n) from fourteen different broiler houses (located in the state of Kentucky) were developed by recording static pressure inside the house when different calibrated fans were turned on. A Fan Assessment Numeration System (FANS) was used for exhaust fan calibration. The air flow exponent (n) ranged from 0.35 to 0.74 (standard error varying from 0.02 to 0.12). The flow coefficient k (m3s-1Pa-n) ranged from 0.55 to 3.55 (standard error varying from 0.1 to 0.45). The results show substantial variability among Kentucky broiler houses.