Among the many methods proposed to predict the presence of fibrosis in patients with chronic hepatitis C are the indices models obtained from serum biochemical tests, the aspartate aminotransferase-toplatelet ratio index (APRI) and the Forns index (FI). To compare the diagnostic accuracy of the Forns index and APRI for predicting cirrhosis. We included 105 patients with chronic hepatitis C and a liver biopsy. The FI and APRI were calculated from the biochemical tests of each patient. Receivers operating characteristic (ROC) curves were calculated to determine the best cutoff to discriminate between cirrhosis (F4), advanced fibrosis (F3-F4), and portal fibrosis (F1) according to the Knodell score. Diagnostic accuracy was assessed by obtaining sensitivity (Sn), specificity (Sp), positive predictive value (PPV) and negative predictive value (NPV) for each of the indices. ROC curves showed that the best cutoff for predicting cirrhosis (F4) for the FI is >7.64, with Sn 62.5% and Sp 91.8% (Area under the curve, AUC = 0.881), for advanced fibrosis (F3 - F4) the best cutoff value is >6.93 with Sn 42.9% and Sp 89.6% (AUC = 0.772). An APRI value of >1.74 was the best predictor for F4 with Sn 75% and Sp 82% (AUC = 0.799), and a cutoff value of >1.7 for predicting F3-F4 with Sn 47.6% and Sp 85.4% (AUC = 0.768). The results confirm the utility of both the FI and APRI for predicting advanced fibrosis and cirrhosis.