Epidemiological data concerning pituitary adenomas are very scarce and in some cases reports are even conflicting. This opinion is at present disputed. The aim of this study was, therefore, to evaluate in the urban area of Fribourg, the prevalence of relevant clinical pituitary adenoma. General practitioners, endocrinologists and gynaecologists were questioned concerning any patient within this agglomeration presenting with a pituitary micro- or macro-adenoma. Among the 44 adenomas, we observed 13 non secreting macro-adenomas, 16 micro- and 9 macro-prolactinomas, 4 cases of acromegaly and 2 ACTH-dependant Cushing diseases. In the studied area we found a prevalence of 80.5 pituitary adenomas per 100,000, or 1 case per 1241 corroborating a greater prevalence of pituitary adenomas than previously believed.