The primary aim of the study was to analyze the endometrioma recurrence rate in patients who underwent laparoscopic excision followed by postoperative long-term regimen of oral contraceptives (OCs). 168 patients who underwent a conservative laparoscopic surgery for endometrioma, during the period between September 2009 and August 2010 in three university hospitals were studied. A long-term OCs therapy was offered to all women following surgery. Patients were randomly divided into three groups according to different progestins used (desogestrel, gestodene, dienogest). Women who refused a postoperative hormonal therapy served as control. Follow-up visits and transvaginal scan were planned at 1, 3, 6, 12, and 24months after surgery. All patients who showed an ultrasound persistence of the endometrioma at 1month follow-up were excluded from clinical analysis. Of the 168 patients, 131 completed the 24months follow-up. Endometrioma recurrence was found in 21 (12.5%) of all patients, it was unilateral in 17 cases while bilateral in 4 cases. The rate of recurrent endometrioma was statistically significant in non-users compared to the long-term OCs treated patients. The current data suggest the usefulness of long-term OCs regimen after conservative surgery for the prevention of ovarian endometrioma recurrence. As a statistical significant difference could not be observed between OCs groups, further study on the individual molecules is required in order to really understand the effect of each of them.