Objective. To present our experience of endoscopic surgery for symptomatic mucus retention cyst of the maxillary sinus. Design. Retrospective study. Setting. Teaching hospital, Israel. Patients. 60 patients with 65 symptomatic cysts of the maxillary sinus who were operated on endoscopically. Only patients with large cysts that filled at least 50% of the sinus space were included. Intervention. A rigid nasal endoscope was used in all cases; most of the cysts were removed through the natural sinus ostium. Results. Cysts recurred in only two patients during the first postoperative year. There were no complications from the procedure. Conclusion. The endoscopic approach to the treatment of maxillary sinus cyst is associated with a low rate of recurrence (3% in this study) and no complications, and we recommend it as the surgical procedure of choice.