The laparoscopic fenestration of functional ovarian cysts with a benign appearance is well known. After aspiration of the contents of the cyst, a window is cut in the cyst wall for an endocystic inspection. In this way, samples for cytology as well as histopathology are obtained. A laparoscopic fenestration was performed on 104 patients. During a mean follow-up time of 20 months, we found a recurrence of 8% in 91 patients. In the presence of pelvic adhesions, the functional cysts tend to reoccur. Corpus luteum cysts have a higher recurrence-rate than follicular cysts. In our study postoperative hormon-therapy recorded no protective effect.