We found that ICOS rs10932029 T>C polymorphism significantly increased the risk of HCC (additive model: adjusted odds ratio (OR), 1.59; 95% confidence interval (CI), 1.13–2.22; P=0.007; homozygote model: adjusted OR, 1.12; 95% CI, 0.31–4.03; P=0.867; dominant model: adjusted OR, 1.58; 95% CI, 1.14–2.19; P=0.007 and recessive model: adjusted OR, 1.02; 95% CI, 0.28–3.68; P=0.974). This evidence concerns the gene ICOS and hepatocellular carcinoma.