In industrialized countries, statistics on health services exhibit a low level of health care use by adolescents, despite the fact that their needs have been widely described. OBJECTIVES: To assess ambulatory health care use by 15-20-year-old teenagers in Switzerland. METHOD: Nine thousand, two hundred and sixty-eight adolescents responded to the self-administered questionnaire distributed in secondary schools and vocational classes for the Swiss Adolescent Health Survey. Questions about visits to general practitioners, specialists and gynecologists, reasons for visit, the availability of a regular health care provider and a confidential health care resource were analysed. RESULTS: Within the previous 12 months, 87.6% of the girls and 75.3% of the boys reported having seen a physician. General practitioners were visited more frequently than specialists. The contact with a specialist was the only one to be related to socio-demographic variables: a lower proportion of reported visits to a specialist was related to apprenticeship, low educational status of parents or rural living area. Thirty-nine percent of the girls reported having seen a gynecologist during the previous 12 months. Two adolescents out of three reported having a personal doctor, and one out of two declared being aware of a confidential health care resource. Girls reported a larger number of reasons for visits than boys: chronic conditions, fatigue, headache and depressive symptoms were the most often cited in a list of ten reasons. Among the subjects who declared a health concern (sleep disturbances, eating disorders, depressive symptoms, smoking or alcohol-related problems) and a need for help, less than 10% declared having seen a health care provider for this reason, even if more than 70% reported contact with a physician within the last 12 months. CONCLUSION: These results show that most adolescents, especially girls, reported recent use of medical services, but did not discuss their health concerns with the doctor. Training should be improved to give better knowledge and counseling skills to health professionals, in order to allow them to address adolescents' health needs.