BACKGROUND BCL9 enhances β-catenin-mediated transcriptional activity regardless of the mutational status of the Wnt signaling components and increases the cell proliferation, migration, invasion, and metastatic potential of tumor cells. The goal of this study was to elucidate the prognostic significance of BCL9 protein expression in hepatocellular carcinoma (HCC) patients. METHODS We evaluated BCL9 protein expression by immunohistochemistry in tumor tissue from 288 primary HCC patients who underwent curative hepatectomy. The impact of BCL9 expression on the survival of the patients was analyzed. The median follow-up period was 97.1 months. RESULTS Nuclear BCL9 protein expression was observed in 74 (25.7%) of the 288 HCCs. BCL9 expression was significantly associated with younger age (p=0.038), higher Edmondson grade (p=0.001), microvascular invasion (p=0.013), and intrahepatic metastasis (p=0.017). Based on univariate analyses, BCL9 expression showed an unfavorable influence on both disease-free survival (DFS, p=0.012) and disease-specific survival (DSS, p=0.032). Multivariate analyses revealed that higher Barcelona Clinic Liver Cancer stage was an independent predictor of both shorter DFS (p<0.001) and shorter DSS (p<0.001). BCL9 expression tended to be an independent predictor of shorter DFS (p=0.078). CONCLUSIONS BCL9 protein expression might be a marker of shorter DFS in HCC patients after curative hepatectomy.