Endosalpingosis as a cause of chronic pelvic pain. Endosalpingosis, a condition characterized by ectopic oviduct epithelium, is diagnosed histologically by the appearance of benign ciliated and nonciliated columnar cells in an abnormal location. Endosalpingosis is typically without symptoms. Our unusual case report shows symptomatic endosalpingosis first seen with chronic pelvic pain. Various aspects of this disease will also be discussed. 