The study comprised 223 patients with airflow obstruction and/or bronchial hyperreactivity from 29 general practices in the catchment area of Nijmegen University. Fifty-six patients were treated by 19 chest physicians, the remaining 167 by their general practitioners (GPs), without specialist care. The specialists treated more allergic patients than the GP (p less than 0.05). No other relevant differences in sex, age, smoking behaviour, and severity of the disease (symptoms, lung function, and bronchial hyperreactivity) could be observed between these two groups of patients. Chest physicians prescribed almost three times as many drugs as GPs. No immediate response to the prescribed bronchodilators was found in 16% of the patients treated by the GPs, nor in 20% of the patients treated by the specialists. We could identify only a weak relationship between the severity of the disease (symptoms and pulmonary function combined) and the prescribed pharmacotherapy: with growing degrees of severity the GP seems to prescribe more bronchodilators, the specialist more inhaled corticosteroids. Prescribed pharmacotherapy should be based on the combination of symptoms, pulmonary function, bronchial hyperreactivity, and reversibility on the prescribed bronchodilators.