['To describe changes of anti-Müllerian hormone (AMH) and inhibin B during low-dose gonadotropin ovulation induction (OI) treatment in women with polycystic ovary syndrome (PCOS), and thus disturbed selection of the dominant follicle.', 'Observational study.', 'A referral fertility clinic.', 'Women with PCOS (n = 48) and normo-ovulatory women (n = 23).', 'Serum AMH, inhibin B, FSH, and E(2) concentrations were measured at start of stimulation, on the day of follicle selection, and at administration of hCG during OI cycles and were compared with concentration measured during the normal menstrual cycle.', 'Development of a single dominant follicle was observed in 92% of all OI cycles, reflected by similar E(2) concentrations compared with those in spontaneous cycles. AMH concentrations were constant during low-dose ovarian stimulation. Inhibin B concentrations remained elevated in patients with PCOS, suggesting prolonged survival of small antral follicles, whereas in controls inhibin B concentrations declined during the late follicular phase.'] Are serum anti-Müllerian hormone and inhibin B concentrations useful predictors of ovarian response during ovulation induction treatment with recombinant follicle-stimulating hormone in women with polycystic ovary syndrome?