BACKGROUND: Benign nonendometriotic ovarian cysts are very common and often require surgical excision. However, there has been a growing concern over the possible damaging effect of this surgery on ovarian reserve. OBJECTIVE: The aim of this metaanalysis was to investigate the impact of excision of benign nonendometriotic ovarian cysts on ovarian reserve as determined by serum anti- Mu¨ llerian hormone level. DATA SOURCES: MEDLINE, Scopus, ScienceDirect, and Embase were searched electronically. STUDY DESIGN: All prospective and retrospective cohort studies as well as randomized trials that analyzed changes of serum anti-Mu¨ llerian hormone concentrations after excision of benign nonendometriotic cysts were eligible. Twenty-five studies were identified, of which 10 were included in this analysis. DATA EXTRACTION: Two reviewers performed the data extraction independently. RESULTS: A pooled analysis of 367 patients showed a statistically significant decline in serum anti-Mu¨ llerian hormone concentration after ovarian cystectomy (weighted mean difference, e1.14 ng/mL; 95% confidence interval, e1.36 to e0.92; I2 ¼ 43%). Subgroup analysis including studies with a 3-month follow-up, studies using Gen II anti- Mu¨ llerian hormone assay and studies using IOT anti-Mu¨ llerian hormone assay improved heterogeneity and still showed significant postoperative decline of circulating anti- Mu¨ llerian hormone (weighted mean difference, e1.44 [95% confidence interval, e1.71 to e1.1; I2 ¼ 0%], e0.88 [95% confidence interval, e1.71 to e0.04; I2 ¼ 0%], and e1.56 [95% confidence interval, e2.44 to e0.69; I2 ¼ 22%], respectively). Sensitivity analysis including studies with low risk of bias and excluding studies with possible confounding factors still showed a significant decline in circulating anti-Mu¨ llerian hormone. CONCLUSION: Excision of benign nonendometriotic ovarian cyst(s) seems to result in a marked reduction of circulating anti-Mu¨ llerian hormone. It remains to be established whether this reflects a real compromise to ovarian reserve.