Objective: To investigate the value of serum anti-Mullerian hormone (AMH) in the clinical diagnosis of polycystic ovary syndrome (PCOS) and evaluation of the efficacy of ovulation induction. Methods: Eighty-five patients with PCOS treated in the Reproductive Medicine Center of Haikou Maternal and Child Health Hospital from January 2020 to September 2021 and 40 healthy women of the same age who came to the hospital for physical examination in the same period were recorded as a PCOS group and a healthy group, respectively, and the serum AMH level of the 2 groups were detected. The PCOS group received ovulation induction drug treatment, and according to the different effects of ovulation induction, they were divided into an ovulation group (n=67) and an anovulation group (n=18). The serum AMH level of the 2 groups before and after the treatment was detected and the decline rate of AMH was calculated. The correlations between serum AMH level and follicle stimulating hormone (FSH), luteinizing hormone (LH), estradiol (E₂), or testosterone (T) in patients with PCOS were analyzed. Receiver operating characteristic (ROC) curve was drawn to analyze the application value of serum AMH detection in the clinical diagnosis of PCOS and the efficacy of ovulation induction. Results: The levels of serum AMH, LH, and T in the PCOS group were higher than those in the healthy group (all P<0.05), and serum AMH was positively correlated with LH and T (r=0.692, 0.516, respectively, both P<0.05). The area under curve (AUC) of serum AMH in the diagnosis of PCOS was 0.814, the best cut-off value was 6.83 ng/mL, the sensitivity, specificity, and accuracy were 84.71%, 72.50%, and 80.80%, respectively. The serum AMH level in the PCOS group was significantly lower than that before the treatment (P<0.05), the serum AMH level in the ovulation group was lower than that in anovulation group before and after the treatment, and the decline rate of serum AMH was higher than that in the anovulation group (P<0.05). The AUC of the decrease rate of serum AMH in evaluating the effect of ovulation induction in PCOS patients was 0.877, which was significantly higher than the baseline value of serum AMH (P<0.05). The best cut-off value of the decrease rate of serum AMH in evaluating the effect of ovulation induction was 29.32%, and the sensitivity, specificity, and accuracy were 83.58%, 83.33%, and 83.53%, respectively. Conclusion: The expression of serum AMH in patients with PCOS increases abnormally and decreases significantly after ovulation induction treatment. The detection of serum AMH can provide an important basis for the clinical diagnosis of PCOS and the evaluation of ovulation induction efficacy.