Within 5 years 181 patients were diagnosed with grade I and grade II atypical hyperplasia (AH) in the curettage material of 4193 specimens at the University Department of Gynecology and Obstetrics in Tübingen. In 62.6% of grade I and in 38.8% of grade II AH, concomitant endometrial polyps were observed, rarely cystic alterations as well. Especially with AH grade II, most polyps exhibited epithelial proliferation. Plurifocality and in situ residuals of AH were seen (grade I 38.5%, grade II 77.3%). In the same time period 345 endometrial carcinomas were found. Due to embedding techniques and the observation that only approximately 60% of the cavum uteri surface is reached via curettage, diagnostic security is quite limited. It has been published that women with AH have a higher risk of developing endometrial carcinoma. A control curettage after 6 months or a wide indication for hysterectomy is recommended after atypical endometrial hyperplasia has been demonstrated.