Environmental measurements were made in different types of poultry confinement buildings. Levels of total dust 1.6 meters above the ground averaged 5.0 mg/m3. Ammonia levels averaged about 13 ppm with peak values of about 50 ppm. To study possible respiratory problems of the people working in these confinement buildings, the ventilatory lung function was measured and an interrogation concerning respiratory symptoms was carried out by 26 (7 females, 19 males) poultry farmers. A very high prevalence (10 of 26) of obstructive ventilatory lung function changes was found. The FEV1 values of the exposed men were significantly lower than the predicted normal values (ECCS). An association between duration of exposure and pulmonary function exists.