Endometriosis lesions are commonly found within the pelvic cavity,while extrapelvic endometriosis is rela-tively rare.Perianal endometriosis is a particularly uncommon condition that is prone to misdiagnosis,and surgical exci-sion is the preferred treatment approach.Our team encountered a young patient with perianal endometriosis who suf-fered a perineal laceration in vaginal delivery for one female baby.At presentation,the patient manifested with a peri-anal mass accompanied by cyclic pain.The patient did not receive specialized diagnosis and treatment from the depart-ment of gynecology,and the perianal lesion slowly regressed to a point where it was no longer visible to the naked eye after another pregnancy and cesarean delivery for one male baby.This article reports the patient's diagnosis and treat-ment along with follow-up results,aiming to share our experience with colleagues.