A total of 671 patients attending two outpatient clinics for pulmonary medicine received a questionnaire about possible alternative treatment of the pulmonary disease for which they were receiving treatment. Six hundred and five questionnaires were answered anonymously. Among the 605 patients, 75 (12%) had received alternative treatment. No differences in the frequencies were observed between men and women. Employment of alternative treatment was most frequent in the age groups 20-29 and 50-59 years. Prolonged illness without definite prospects of cure such as chronic bronchitis and asthma resulted in employment of alternative treatment more frequently than briefer illness without possibility of cure (cancer of lung) or with the possibility of cure (tuberculosis, pneumonia). The patients had practically always consulted their general practitioner before the alternative therapist (94%). Half of the patients had improved, half were unchanged and only a few per cent had deteriorated. In the majority of cases, the expenses were moderate but isolated patients had, however, paid more than 10,000 Danish crowns (approximately pounds 1,000) for the alternative treatment.