Objective: Epithelial-mesenchymal transition (EMT) is a critical early event for the invasion and metastasis of many carcinomas. In the present study, we examined EMT markers in the residual cancer cells of hepatocellular carcinoma (HCC) after radiotherapy. Methods: Eight patients with large HCC who underwent hepatectomy with preoperative radiothera- py were studied. The expressions of E-cadherin and vimentin were determined immunohistochemically in the residual cancer cells of HCC following radiotherapy, and also in the pre-radiotherapy biopsy cancer cells. Results: Histological analysis showed that some residual cancer cells of HCC displayed an elongated spindle or fibroblast-like shape. The expression of E- cadherin was markedly reduced or negative in the spindle residual cancer cells, but the expression of vimentin significantly in- duced. However, the above changes were not found in the pre-radiotherapy biopsy cancer cells. Conclusion: EMT is induced in the residual cancer cells of HCC following radiotherapy, which may facilitate the systemic dissemination of cancer cells. Objective: Epithelial-mesenchymal transition (EMT) is a critical early event for the invasion and metastasis of many carcinomas. In the present study, we examined EMT markers in the residual cancer cells of hepatocellular carcinoma (HCC) after radiotherapy. Methods: Eight patients with large HCC who underwent hepatectomy with preoperative radiothera-py were studied. The expressions of E-cadherin and vimentin were determined immunohistochemically in the residual cancer cells of HCC following radiotherapy, and also in the pre-radiotherapy biopsy cancer cells. Results: Histological analysis showed that some residual cancer cells of HCC displayed an elongated spindle or fibroblast-like shape. The expression of E-cadherin was markedly reduced or negative in the spindle residual cancer cells, but the expression of vimentin significantly-duced. However, the above changes were not found in the pre-radiotherapy biopsy cancer cells. Conclusion: EMT is induced in the residual cancer cells o f HCC following radiotherapy, which may facilitate the systemic dissemination of cancer cells.