ObjectiveTo describe the anatomic variety of congenital cervical atresia and to explore the relationship between this disorder and pelvic endometriosis. MethodsIn a retrospective study, records were reviewed for 96 patients with a confirmed diagnosis of congenital cervical atresia treated at a center in Beijing, China, between January 1984 and October 2014. Data on demographic parameters, symptoms, anatomic features, and endometriosis were obtained and analyzed. ResultsOf the 96 patients, 54 (56%) had pelvic endometriosis, 23 (24%) had a uterine malformation, 75 (78%) had a vaginal malformation, and 12 (13%) had a urinary malformation. The patients with a delay from first symptoms to surgery of more than 1year had a higher incidence of endometriosis than did those with a delay of 1year or less (45/71 [63%] vs 7/23 [30%]; P=0.006), and this trend was not related to the severity of endometriosis (P=0.658). Among the 31 patients with unilateral endometrial cysts, 20 (65%) had left-sided cysts and 11 (35%) had right-sided cysts (P=0.005). ConclusionMore than half of patients with congenital cervical atresia had pelvic endometriosis. Early diagnosis and surgery seem to be necessary to prevent endometriosis among patients with congenital cervical atresia.