OBJECTIVE: To evaluate the correlation between serum levels of anti-Mullerian hormone (AMH) and ovarian response to mild stimulation in normoovulatory women and anovulatory women with polycystic ovary syndrome (PCOS). METHODS: Seventy-four cycles of mild stimulation (clomiphene citrate+gonadotropin followed by timed intercourse or intrauterine insemination) performed in normoovulatory women (57 cycles) and anovulatory women with PCOS (17 cycles). Ovarian sensitivity was defined by the number of mature follicles (> or =14 mm) on triggering day per 100 IU of gonadotropin. A correlation between ovarian sensitivity and the baseline serum AMH level (absolute or multiples of the median [MoM] value for each corresponding age) was calculated. Correlation between ovarian response and serum AMH level was evaluated. RESULTS: Ovarian sensitivity to mild stimulation was positively correlated with absolute serum AMH (r=0.535, p<0.001) or AMH-MoM value (r=0.390, p=0.003) in normoovulatory women, but this correlation was not observed in anovulatory women with PCOS (r=0.105, p>0.05, r=-0.265, p>0.05, respectively). CONCLUSION: Ovarian response to mild stimulation is possibly predicted by the serum AMH level in normoovulatory women, but not in anovulatory women with PCOS.