The postoperative cheek cyst develops as a delayed complication during many years after surgical intervention in the maxillary sinus. Thirty two cases of postoperative cheek cyst were treated and studied clinically in the department of otolaryngology, St. Mary's hospital & Kangnam St. Mary's hospital, from 1980 to 1986. Most of the patients were in their 30s and 40s at the time of diagnosis, and the postoperative duration was between 10 and 29 years. The most common symptoms were swelling and/or pain of the cheek. The cysts were treated surgically in all cases. The results of our analysis are discussed.