Purpose of investigation: To determine a cut-off value for beta-human chorionic gonadotropin (beta-hCG) concentrations to predict dizygotic twinning after in vitro fertilization (IVF) and double embryo transfer (DET). Materials and Methods: This retrospective cohort study included 233 women who conceived after DET at IVF center, Hacettepe University Faculty of Medicine. Patients with serum beta-hCG concentration >= 25 IU/1 assayed on day 14 after oocyte retrieval were included into the study. Results: Lower serum (beta-hCG concentrations were observed in non-viable pregnancy when compared to their viable counterparts. In addition, twins exhibited higher (beta-hCG concentrations than singletons did. Receiver operator characteristic (ROC) curve analysis showed a significant relationship between serum beta-hCG concentrations and the occurrence of twin pregnancy (area under the curve = 0.85, 95% confidence interval = 0.79-0.91, p < 0.001). For twin pregnancy, when beta-hCG >= 175 IU/1, sensitivity was 77.3%, specificity was 80.0%, positive predictive value (PPV) was 48.2%, and negative predictive value (NPV) was 93.8%. Conclusion: beta-hCG >= 175 IU/1 might be used as a new cut-off value for early prediction of viable dizygotic twins following IVF-DET treatment cycles.