Two hundred and fifty-five admissions for acute asthma with a minimum 25% PEFR improvement in patients aged 15-44 years were studied in 1991-1992. Two hundred of these patients were in the white ethnic group (84 male; 116 female) with 33 (17.4%) being readmissions (15 male; 18 female). Fifty-five admissions (19 male; 36 female) were in the Indian subcontinent (ISC) ethnic group with 3 (5.5%; all female) readmissions. The readmission rate was significantly higher in the white ethnic group (chi 2 = 4.83; 0.05 < P < 0.01). Admission rates per thousand population in 5-yr cohorts were calculated from the 1991 Census data. The admission rate was higher in the ISC ethnic group in all cohorts except females aged 15-19 years, and was significantly higher in males aged 15-19 years and 40-44 years, and in all four cohorts between 25-44 years in females. Initial PEFR and % initial PEFR/highest PEFR did not suggest increased severity of asthma in the ISC ethnic group.