Abstract: Objective：To solve the symptoms of achalasia complicated with osteogensis imperfecta through peroral endoscopic myotomy (POEM). Methods：The 21-year-old male patient, being diagnosed as achalasia complicated with osteogensis imperfecta, underwent POEM under general anesthesia after preoperative assessment of achalasia (Eckardt score of 7). The mucosal incision was made at a distance of 28 cm from the incisor,then the gastroscope entered the submucosal layer and tunnel in it, and myotomy was performed about 29 cm from the incisor extending 2 cm into the cardia. Electrocoagulation was performed to stop bleeding and the mucosal incision was then closed. Results：The operation was completed successfully in about 28 minutes. The stomach tube was removed 30 h after surgery. The patient was discharged in a stable condition on the fourth postoperative day. The follow-up result showed no recurrence in symptom with Eckardt score of 0 two weeks after operation. Conclusions：POEM is a feasible and effective way for achalasia of cardia complicated with osteogenesis imperfecta.