Background:Since 1985, nurse-run asthma clinics have been developing and are now widespread in the United Kingdom, having been greatly stimulated by the New Contract for General Practice (1990). To date, there have been few definitive studies evaluating such clinics. This study, in two adjacent general practices in semi-rural Somerset, evaluates the effect of nurse-run clinics on patients' symptoms, pulmonary function, and healthcare utilisation over a four-month period. Methods:One hundred and twenty-nine subjects, aged 2-79 years, were recruited from the two practices over a one-year period (1991-1992). All patients identified in either practice who had used preventive therapy in the preceding 12 months were eligible and were included if they had a positive exercise or reversibility (20%) test and had not previously received formal asthma education. A pre- and post-experimental study design was used. Subjects' symptoms, pulmonary function, and health care in the preceding eight weeks were assessed at intake and at 16 weeks; the nurse education being delivered at intake, one and four weeks. Results:Both mean number of days off work/school and mean number of nights on which waking occurred fell (p < 0.001). Peak expiratory flow rates and forced expiratory volumes improved during the study period (p < 0.001 and p < 0.01 respectively). Use of antibiotics, oral steroids, and rescue bronchodilator use all improved significantly (p < 0.001). Physician attendances were also reduced. Conclusions:A nurse-run asthma clinic in general practice is an effective way to improve symptoms, pulmonary function, and health care utilisation for asthmatic patients.