A skin test using buckwheat extract was performed on 182 cases of bronchial asthma. Thirty-three of them showed a positive skin test to buckwheat extract. Buckwheat allergy (bronchial asthma, urticaria, allergic rhinitis, allergic gastroenteropathy and allergic conjunctivities) was found in 19 (57.6%) of the 33 cases showing a positive skin test to buckwheat extract. Basophils from 8 cases of buckwheat asthma showed a strong response to buckwheat extract, although basophils from 10 cases with a postive skin test only, without buckwheat allergy, did not response to buckwheat extract. Bronchial asthma induced by buckwheat (16 of the 19 cases) had some special features. Their asthma attack was induced by the introduction into the body through either mouth or airway and started in childhood. Buckwheat pillows were used in 13 of the 19 cases. Ten of the 13 cases obtained alleviation of asthma upon discontinuation of buckwheat pillows. Most of the buckwheat asthma patients showed a high serum IgE level and had a hereditary factor. The results showed that cases of buckwheat asthma might be sensitized in their childhood.