BACKGROUND: Transforming growth factor (TGF)-β is involved in many physiologic processes, it often promotes metastasis, and its high expression is correlated with poor prognosis. In the present study, we analyzed the correlation between transforming growth factor beta 1 (TGF-β1) expression and prognosis in intrahepatic cholangiocarcinoma RESULTS: We examined the expression of TGF-β 1 in 78 intrahepatic cholangiocarcinomas by immunohistochemistry and correlated the expression with clinicopathological parameters. TGF-β1 was expressed in 37 of 78 (47.4 %) intrahepatic cholangiocarcinomas. The expression of TGF-β 1 was significantly correlated with lymph node metastasis, distant metastasis, and tumour recurrence. Patients with TGFβ1-positive tumours had significantly shorter survival time. In a multivariant analysis, the expression of TGF-β1 and the tumour stage were independent prognostic factors CONCLUSIONS: Our data suggest that expression of TGF-β1 is a novel prognostic marker for intrahepatic cholangiocarcinoma