In this study, three immunologic tests, skin prick test, RAST, and basophil histamine-release test (BHRT), were compared by provocation in the diagnosis of occupational asthma and rhinitis. Twenty-three positive bronchial or nasal challenges were performed on 16 patients (six farmers, six bakery workers, and four food industry workers) and asthma or rhinitis was diagnosed as caused by cereal flour or grain, cow epithelium, storage mites, garlic, or soy dust. A control group consisted of 12 patients, of whom four (two bakery workers, one food industry worker, and one farmer) were challenge-negative, and the rest suffered from pollen allergy and seasonal rhinitis and were not challenged. The sensitivity and specificity of the prick test, RAST, BHRT, and a panel of them were as follows: 74 and 89%, 57 and 86%, 78 and 93%, and 91 and 71%, respectively. The overall concordance among these three type I allergy tests or between immunologic tests and challenge was relatively good.