OBJECTIVE It has been recognized that HBV infection andalcohol consumption are two important risk factors for primaryhepatocellular carcinoma (HCC). Recently, the role of clonorchiasisas a risk factor for HCC is controversial. We aimed to investigatewhether these factors increase the risk of HCC in Guangxi, China.METHODS A hospital-based, case-control study of HCCwas conducted from July 2005 to July 2007. We enrolled 500consecutive patients with HCC as an experimental group and 500patients without tumor in liver as a control group. The risk factorsthat the patients were exposed to were assessed.RESULTS Comparing the risks of developing the HCC, wefound out the following results. The risk of developing HCC forthe patients with clonorchiasis was 5 folds of that for the patientswithout clonorchiasis (OR = 5.0; 95% CI: 3.1-8.1), and the risk forthe patients with alcohol consumption was 3 folds of that for thepatients without drinking alcohol (OR = 3.4; 95% CI: 2.3-4.9), andsimilarly, the risk for the patients with HBV infection was 21 timesof that for the patients without HBV infection (OR = 20.6; 95% CI:14.3-29.7). According to crossover analysis, there was significantinteraction among clonorchiasis, HBV infection and alcoholconsumption, with synergistic indices greater than 1. The etiologicfractions attributed to these interactions [EF (A x B)] are 0.7465,0.5789 and 0.5506, respectively.CONCLUSION Clonorchiasis, HBV infection and heavy alcoholconsumption are independent risk factors for developing HCC inour population in Guangxi, and as they can interact synergistically,the risk of developing HCC is increased. Data from this study mayindicate new prevention strategies of developing HCC in high-riskindividuals. OBJECTIVE It has been recognized that HBV infection and alcohol consumption are two important risk factors for primary hepatocellular carcinoma (HCC). Recently, the role of clonorchiasis as a risk factor for HCC is controversial. We aimed to investigate whether these factors increase the risk of HCC in Guangxi, China.METHODS A hospital-based, case-control study of HCCwas conducted from July 2005 to July 2007. We enrolled 500consecutive patients with HCC as an experimental group and 500patients without tumor in liver as a control group. The risk factorsthat the patient were exposed The risk of developing HCC forthe patients with clonorchiasis was 5 folds of that for the patients with out clonorchiasis (OR = 5.0; 95% CI: 3.1-8.1) , and the risk forthe patients with alcohol consumption was 3 folds of that for thepatients without drinking alcohol (OR = 3.4; 95% CI: 2.3-4.9), and similar, the r isk for the patients with HBV infection was 21 times of that for the patients without HBV infection (OR = 20.6; 95% CI: 14.3-29.7). According to crossover analysis, there was significant interaction among clonorchiasis, HBV infection and alcoholconsumption, with synergistic indices greater than 1. The etiologicfractions attributed to these interactions [EF (A x B)] are 0.7465, 0.5789 and 0.5506, respectively. CONCLUSION Clonorchiasis, HBV infection and heavy alcohol consumption are independent risk factors for developing HCC in population in Guangxi, and as they can interact synergistically, the risk of developing HCC is increased. Data from this study mayindicate new prevention strategies of developing HCC in high-riskindividuals.