BACKGROUND Hepatocellular carcinoma (HCC) causes many deaths worldwide every year, especially in Asia. It is characterized by high malignancy, recurrence, and short survival time. Inflammation is closely related to the initiation and development of HCC. Tumor necrosis factor-α (TNF-α), an essential inflammatory mediator, has been studied as a potential therapy target in many cancers. However, its potential role in HCC diagnosis and therapy is still unclear. MATERIAL AND METHODS In our study, we detected the TNF-α expression in both human HCC tumor tissue and HCC cell lines HepG2 and HuH7. Then, we detected the effect of anti-TNF-α treatment and it synergistic function with 5-FU in an HCC xenograft mouse model and in HCC cell lines. RESULTS Survival analysis and Cox regression analysis based on 97 HCC patients indicated that a high level of TNF-α is an independent predictor of poor survival in HCC patients. Anti-TNF-α treatment by infliximab synergizes with Fluorouracil (5-FU) by promoting apoptosis of HCC tumor cells through complement-dependent cytotoxicity (CDC) and antibody-dependent cellular cytotoxicity (ADCC) effects. CONCLUSIONS Based on these data, we conclude that anti-TNF-α treatment could be a good way to increase the effect of classic chemotherapy of HCC patients, especially for the patients who have modest response to classic chemotherapy, such as 5-FU. TNF-α could also be used as a biomarker to help in early diagnosis of HCC.