Proliferative epithelial lesions of the oviduct have been called adenomatous hyperplasia or carcinomain situ. In order to assess the incidence and significance of these lesions, we sectioned entire oviducts from 124 nonselected hysterectomies. We found 23 cases (18.5%) with lesions corresponding to those described in the literature. We have found no justification for diagnosing and treating these lesions as carcinomain situ. There appears to be an association with salpingitis.