To characterize asthma emergencies, all patients attending the hospital because of an asthma attack in 1 year were studied. Of the 212 patients concerned, 148 attended the hospital once, 34 twice and 30 three times or more. The total number of visits was 351. The mean age of the patients was 50 (15-85) years, and 32% of those under 65 years were receiving a pension because of asthma. Eleven patients (5%) had drinking problems, and 62 (29%) had treatment for other diseases. Atopy was diagnosed in 83 patients (39%). Of the patients with one, two or more numerous visits 39, 74 and 90%, respectively, were taking oral steroids, whereas the corresponding figures for those using inhaled steroids were 34, 71 and 61%. Medical treatment seemed to be inadequate more often among the frequent visitors. Seasonal variation in visits was evident, the rates being lowest in July and highest in March. Time-of-day variation was also found, visits being most common from 10 to 11 a.m.