It has been reported that among mushroom farmers, respiratory diseases such as hypersensitivity pneumonitis can be developed by inhalation of mushroom (Pleurotus ostreatus) spores. For the evaluation of respiratory symptoms among mushroom farmers, a questionnaire was made. The Questionnaire included general characteristics, past occupational histories, durations of the mushroom cultivation and characteristics of the symptoms. Following the questionnaire we interviewed the 72 mushroom farmers (12 males, 10 females) from Kyungbuk Province. We also examined white blood counts, erythrocyte sedimentation rates, eosinophil counts and total IgE counts for the 5 farmers. The results obtained are as follows. 1. The mean age among the 22 mushroom farmers was 46.9 years, and the mean duration of cultivation was 7.5 years. 2. Among the 22 mushroom farmers. 18 farmers (81.8 %) suffered from respiratory symptoms at work. The main symptom was coughing (100.0%), followed by chilling sensation (50.0 %), sputum (38.9 %) and sore throat (27.8 %). 3. Coughing and other associated symptoms occurred during work and disappeared after work or several days later when the exposure had been stopped. 4. Total IgE counts were elevated in all farmers examined the test. With above results, the respiratory symptoms that developed among mushroom farmers were typical patterns of hypersensitivity pneumonitis. Epidemiological studies and preventive measures for mushroom farmers should be established.