OBJECTIVE To study the relationship between mutation of p53 gene and hepatocellular carcinoma (HCC). METHODS Sixty-five cases of HCC from Nanning prefecture of high aflatoxin (AFB1) exposure were studied by polymerase chain reaction and restrictive fragment length polymorphism (PCR-RFLP) analysis to examine the exon 7 of p53 gene in HCC. RESULTS 58.5% of the cases were found to show mutation at codon 249 of p53 gene; 63.6% for the HCCs with HBsAg negative, and 57.4% for those with HBsAg positive; 88.9% for those with metastasis, and 46.8% for those with no metastasis. The mutation rate of p53 gene was 10.0%, 55.2% and 80.8% in the well-, moderately- and poorly-differentiated HCC respectively. CONCLUSIONS AFB1 is the most important agent for the mutation at the hot-spot, and hepatitis B virus is the synergistic risk factor. Further study indicated that the p53 gene mutation is correlated with the differentiation and the metastasis of HCC and may serve as an important prognostic factor.