Objective To evaluate predictive role of day-3 serum antiMüllerian hormone (AMH) levels and antral follicle count (AFC) in ovarian hyperstimulation syndrome (OHSS) in patients undergoing IVF/ICSI cycles. Materials and methods Forty-one women with moderate/ severe OHSS and 41 age matched women without OHSS were compared to evaluate the predictive value of certain risk factors for OHSS. AFC, and E 2 , FSH, LH, AMH, inhibin-B levels measured on day 3 of the menstrual cycle before controlled ovarian hyperstimulation. Results Mean FSH was significantly lower (p<0.0001); and mean LH, AFC and AMH were significantly higher in women with OHSS compared to women without OHSS (p=0.049, p<0.0001 and p<0.0001, respectively). There was no significant difference in inhibin B (p=0.112) and estradiol (p=0.706) between the groups. The ROC area under curve (AUC) for AMH presented the largest AUC among the listed risk factors. AMH (AUC=0.87) and AFC (AUC=0.74) had moderate accuracy for predicting OHSS while Inhibin B (AUC=0.58) and LH (AUC= 0.61) had low accuracy. The cut-off value for AMH 3.3 ng/mL provided the highest sensitivity (90%) and specificity (71%) for predicting OHSS. It's positive (PPV) and negative predictive values (NPV) were 61% and 94%, respectively. The cut-off value for AFC was 8 with 78% sensitivity, 65% specificity, 52% PPV and 86% NPV. Conclusion Measurement of basal serum AMH and AFC can be used to determine the women with high risk for OHSS.