Objectives: Up to 32% of women experience anatomic recurrence after conservative surgery for endometriomas, while pain recurs in 10-40% of cases. Long-term postoperative hormonal therapy is recommended to prevent disease recurrence. We evaluated the efficacy of long-term therapy with estroprogestins (EPs) or progestins (Ps) in preventing endometrioma recurrence, as identifiable cysts and subjective symptoms, after laparoscopic excision.Design: This retrospective cohort study included 375 women submitted to laparoscopic endometrioma excision. Women were followed up at 6 and 12 months and then yearly after surgery. Based on postoperative medical therapy, women were divided into 4 groups: nonusers, cyclic EP users, continuous EP users, and progestogen users. Materials, Setting, Methods: Anamnestic and anthropometric characteristics were collected as well as clinical and surgical data. Gynecological examination, and transvaginal and transabdominal ultrasound scans were performed. Pain (numerical rating score >5) and endometrioma recurrence at ultrasound (ovarian cyst with typical sonographic features ≥10 mm in mean diameter) were recorded at each examination. The reoperation rate in women with recurrence was investigated.Results: The median follow-up was 3.7 years with a maximum of 16.7 years. Most patients used EPs (119 cyclic and 61 continuous users), 95 used P, and 100 were nonusers. In 135 women (36%), endometriotic cyst recurrence was diagnosed, with a mean diameter of 18.7 ± 10.8 mm (range 10-55 mm). The median recurrent cyst-free time was 7.9 years (95% CI 5.8-10.8). Dysmenorrhea was the first symptom to reappear, affecting 162 patients (43.2%). Upon multivariable regression analysis, continuous users had a lower risk of relapse (OR 0.56, 95% CI 0.32-0.99), in terms of both cysts and symptom recurrence, than patients who received no medications. The reoperation rate was 16.2%.Limitations: The main limitation of this study is its retrospective design. Also, women switching therapies throughout the follow-up period were sorted into one of the study groups based on the longest treatment taken, without considering the discontinuation rates.Conclusions: Long-term EPs, administered in a continuous regimen and starting immediately after conservative surgery for endometriomas, seem to reduce the disease recurrence risk. [ABSTRACT FROM AUTHOR]