SummaryA total of 108 samples of sputum obtained from twenty patients with bronchial asthma were examined for appearance of basophils and eosinophils. Both cell types are present in sputum during an asthmatic attack and disappear at the conclusion of the attack. Their presence correlates with the severity of the disease. It has previously been demonstrated that the blood basophils count falls during attacks of bronchial asthma, and the present study suggests that basophils move from the blood stream into bronchial tissue during the acute phase of an asthmatic attack.