['To determine stimulated serum anti-Mllerian hormone (AMH) levels in men with different causes of subfertility.', 'We prospectively studied 82 subfertile men and 31 controls. The subfertile men underwent a diagnostic procedure to identify the causes of subfertility. Study parameters included testicular volume, levels of follicle-stimulating hormone, luteinizing hormone, total testosterone, prolactin, inhibin B and AMH, and sperm parameters.', 'Clinical diagnoses in subfertile men were idiopathic non-obstructive azoospermia (n = 26, 32%), idiopathic non-obstructive dyspermia (n = 17, 21%), varicocele (n = 16, 20%), cryptorchidism (n = 10, 12%) and other diagnoses (n = 13, 16%). Serum AMH levels in subfertile men were 60% lower than in controls [median (interquartile range) 4.6 (3.6) vs. 11.6 (7.7) ng/ml, p 0.001], with no significant differences among the different groups of subfertile men.'] Do serum anti-Müllerian hormone levels differentiate control from subfertile men but not men with different causes of subfertility?