From 1985 to 1991, 73 hysterectomies were performed on patients suffering from histologically demonstrated adenomatous hyperplasia, grades 1–3, at the Kiel University Hospital of Gynecology. The operations were done within a month from the diagnosis. Three of the patients were under 40 years of age. An exact correspondence between the grade of adenomatous hyperplasia in the abraded material and the uterus specimen was found in only 44% of the cases. In the patients over 40 with adenomatous hyperplasia of any grade demonstrated in the abraded material, an already well-differentiated endometrial carcinoma was found in 16% of the cases, while such a carcinoma was found in 57% of the cases with grade 3 adenomatous hyperplasia! Even though drug therapy with gestagen may have a beneficial effect, a hysterectomy is nevertheless the treatment of choice for adenomatous hyperplasia of grade 2 and grade 3 in patients over 40 because it is not absolutely certain from a diagnostic point of view that the material is representative of the entire mucosa. In women under 40 years of age it is necessary to plan therapy on an individual basis.