This preliminary prospective study investigated serum anti-Müllerian hormone (AMH) through correlations to other basal parameters (123 patients) and according to ovarian response to 75 IU recombinant follicle-stimulating hormone (rFSH)/day (62 patients) in ovulatory patients' first rFSH treatment cycle before intrauterine insemination. Mean age of the patients was 33 years. Serum AMH significantly correlated to age (r=-0.38), antral follicle count (AFC) (r=0.68), ovarian volume (r=0.40), FSH (r=-0.31), (P2-3 mature follicles or dose reduction). There was a significant trend over response groups for body weight (P=0.005), body mass index (P=0.035), AFC (P=0.031) and FSH (P=0.001). Serum AMH median (IQR) was 10.6 pmol/l (6.9-18.2) in the 23 patients who achieved an ongoing pregnancy versus 10.5 (5.9-17.2) in the 100 non-pregnant women. Serum AMH may not be the best marker of the ovarian response in these patients.