alpha-Fetoprotein (AFP) is often elevated in hepatocellular carcinoma (HCC). This study was to elucidate the significance and related factors of AFP elevation in HCC in 781 unifocal HCCs receiving curative hepatectomy. We showed that high AFP (> 200 ng/ml), which was associated with AFP mRNA expression in HCC (p = 0.00001), correlated with major clinicopathologic factors. Younger age (< or = 55 years; p=0.00001), hepatitis B surface antigen (HBsAg) in serum (p=0.00001), p53 mutation (p=0.008), large tumor (p=0.00001), vascular invasion (p=0.00001) and early tumor recurrence (p=0.00001) were significant associates of high AFP, while anti-HCV in serum and beta-catenin mutation in HCC had less frequent high AFP (p=0.013 and < 0.0001, respectively). We also showed that HCC with high AFP had a lower 10-year survival (p < 0.0001), particularly in large HCC (p < 0.0001). At univariate analysis, high AFP (p < 0.0001), HBsAg positivity (p=0.05), p53 mutation (p=0.0004), liver cirrhosis (p=0.0094), large tumor (p=0.0003), vascular invasion (p < 0.0001) and early recurrence (p < 0.0001) were significant unfavorable prognostic factors. In Cox proportional hazards regression analysis, high AFP remained a borderline significance (OR=1.2; CI=1.0-1.4) after adjustment for the effect of tumor size and tumor stage (p=0.0821). Furthermore, the detection of AFP mRNA in the liver of AFP mRNA-positive HCC was associated with more frequent early recurrence (p=0.0026) and might be a useful marker of intrahepatic spread. We therefore conclude that AFP elevation, more than a coincidental epiphenomenon, appears to contribute to vascular invasion and HCC progression and help to identify subsets of HCC patients with increased risk for early recurrence and poor prognosis after hepatectomy.