Background: The aim of this study was to compare the difference of serum anti-mullerian hormone (AMH) level between endometriotic cyst (EC) and non-ECs, and postoperative change in AMH level among patients who underwent single port laparoscopic (SPL) ovarian cyst enucleation. Methods: A retrospective cohort study was conducted to patients who underwent SPL ovarian cystectomy for benign cyst from Jan. 2017 to Jun. 2018. The patient who checked serum AMH levels preoperatively and at postoperative day 10 (POD 10d) and 3 months (POD 3m) were selected and AMH level change were analyzed according to the tumor type and vasopressin use. Results: In total, 180 patients were enrolled in this study with the mean age of 32.57 + 7.23 years. Majority of the cysts was EC (62%) followed by mature cystic teratoma (27%) and other histologic types (11.1%). The serum AMH values at the three points of measurement were significantly lower in EC compared with non-EC (median AMH at Pre-op: 1.97 vs. 3.83 ng/ml, P<0.001; POD 10d: 1.00 vs, 3.17 ng/ml, P<0.001; POD 3m: 1.19 vs. 3.6 ng/ml, P<0.001). There was a significant change in the serial values of AMH in EC across the three points of measurement [2.74 (pre-op) vs. 1.53 (POD 10d) vs. 1.85 (POD 3m) ng/ml, P <0.001) but not in non-EC [4.18 (pre-op) vs. 3.39 (POD 10d) vs. 3.74 (POD 3m) ng/ml, P = 0.205). There was a significantly greater difference in AMH from the baseline to POD 10d (1.54 vs. 0.73; P<0.001) and POD 3m (1.94 vs. 0.57; P<0.001) in patients who underwent bilateral cystectomy compared to those who underwent unilateral cystectomy. Vasopressin injection during surgery does not have a significant effect in AMH level. Conclusion: The basal AMH in patients with EC were significantly lower than those with non-EC. This result suggests that the ovarian reserve of patients with EC is lower than in patients with non-EC. Also, the ovarian reserve was more likely to be affected by laparoscopic cystectomy in EC compared to non-ECs. However, non-EC enucleation could be performed without significant decrease in ovarian reserve by SPL.