Abstract: Objective To investigate the effect of ultrasound-guided interventional therapy on massive pelvic cysts. Methods From 2006 to 2017, 57 cases with massive pelvic cysts were treated in our department. Of the 57 cases, 4 cases were with chocolate cyst, 29 cases with pelvic encapsulated effusion, 5 cases with parovarian cyst, and 19 cases with ovarian cyst. The volume of the cyst was estimated by preoperative ultrasound examination and compared with the intraoperative extracted liquid volume. Percutaneous ethanol sclerotherapy or antibiotic fluid irrigation with indwelling treatment was performed under the guidance of ultrasound. Results The effective rate at 1 year was 84% for all cases, and it was 100% for chocolate cyst, ovarian cyst and parovarian cyst, and 69% for pelvic encapsulated effusion. Conclusion Ultrasound-guided interventional therapy is simple, safe, effective and repeatable for massive pelvic cysts with less pain and complications.