Cholangiocarcinoma (CCA) is a poor prognosis cancer that presents with metastatic disease. This cancer expresses MUC5AC, a mucin which normally co-expresses with trefoil factor family 1 (TFF1) protein. TFF1 is a signalling protein that can activate epithelial cell invasion and has been considered as a metastasis stimulating agent. The aim of this study was to determine the co-expression of TFF1 and MUC5AC in CCA tissues and examine the activity of TFF1 for stimulating the invasive property of CCA cell lines. Methods: In this study, TFF1 and MUC5AC were detected in CCA tissues by using immunohistochemistry