In Switzerland the ambulatory care system considered as a whole, is not sufficiently known, especially as regards number and location of institutions and professionals, forms of cooperation and measures of activity. The research team "Ambulatory care" of the Swiss National Research Programme No. 8 tries to fill that gap in the cantons of Fribourg and Vaud in pointing out to the recent but lasting numeric growth in all professions contributing to ambulatory care. The latter represent 42% of all health workers, and among them the physicians are 1/7. This study attracts attention to institutions and organizations like those providing home care and outpatient departments of regional hospitals.