The aim of this study was to determine noninvasive predictive factors of significant liver fibrosis in patients with increased serum aminotransferases associated with features of metabolic syndrome (abdominal obesity, systemic hypertension, fasting hyperglycemia, and dyslipidemia). One hundred seventy-three patients were prospectively examined, regardless of alcohol consumption. Biometric, metabolic, and hepatic biochemical variables were tested for association with fibrosis assessed on liver biopsy according to the Metavir score system. Significant fibrosis, defined as Metavir scores F2, F3, or F4, was observed in 42 of 173 patients (24%). A logistic regression model and receiver operating characteristic curve were used to construct a simple index predictive of significant fibrosis. None of the patients with serum hyaluronate levels of 35 microg/L or less had significant fibrosis. In patients with serum hyaluronate levels >35 microg/L, no case of fibrosis stage F3 or F4 was found when serum carbohydrate-deficient transferrin/transferrin ratio was less than 0.9. In conclusion, in patients with increased serum aminotransferases associated with features of metabolic syndrome, a simple algorithm, including serum hyaluronate and serum carbohydrate-deficient transferrin/transferrin ratio, allows the exclusion of clinically relevant hepatic fibrosis, regardless of current or past alcohol consumption.