The chance of infertile patients conceiving is related to factors like female age and duration of infertility. This prospective observational study evaluated whether the results of ovarian reserve tests, including the novel marker serum anti-Mullerian hormone (AMH), were of additional value in predicting ongoing pregnancy. Two hundred and twenty-two patients diagnosed with unexplained infertility or mild male factor (total motile count>10x10(6)) on the basis of the infertility work-up were prospectively included. Antral follicle count, AMH, inhibin B, FSH and oestradiol concentrations were determined during the early follicular phase. Outcome measures were treatment-dependent and treatment-independent ongoing pregnancy and time to ongoing pregnancy. There were 159 ongoing pregnancies, 52 of which occurred spontaneously. Pregnant patients were significantly younger than those who did not become pregnant (median age 32.4 versus 34.9 years, P<0.001) and FSH concentrations were higher in non-pregnant patients (median 6.8 versus 7.6 IU/l, P=0.04). Only age (hazard ratio 0.93, 95% CI 0.90-0.97) and whether or not the patient was undergoing treatment (hazard ratio 8.10, 95% CI 5.66-11.61) were significantly associated with time to ongoing pregnancy. Ovarian reserve tests, other than chronological age, seem of limited value in predicting (time to) ongoing pregnancy in patients with unexplained and mild male infertility.