Extrahepatic bile duct cancer is a high mortal malignancy. Angiopoietin (Ang) and its receptor Tie, which are known to contribute to angiogenesis, have recently been reported to participate in the proliferation and differentiation of malignant tumor cells. The aim of this study is to investigate the expression and the significance of Ang-1, 2 and Tie-2 in extrahepatic bile duct carcinoma cells. We used immunohistochemistry to study 119 cases of surgically resected human extrahepatic bile duct carcinoma, and Reverse Transcription-Polymerase Chain Reaction (RT-PCR) to confirm the expression of Ang-1, 2 and Tie-2 mRNA. Among these 119 cases, 52 (43.7%), 50 (42.0%) and 89 (74.8%) cases showed positive staining for Ang-1, 2 and Tie-2, respectively, in bile duct carcinoma cells. In 38 cases of normal mucosa, 6 (15.8%), 10 (26.3%) and 9 (23.7%) cases were positive for Ang-1, 2 and Tie-2, respectively. The positivity for Ang-1 and Tie-2 in normal mucosa was significantly different from all carcinomas (p<0.01 and p<0.001, respectively). We found no significant correlation between Ang-1 and Ang-2 expression and other clinicopathological factors such as histological differentiation, grade of tumor invasion or survival rate after surgery. In contrast, Tie-2 expression correlated significantly with degree of desmoplasia, cancer stage and survival of patients. RT-PCR analyses of five surgically resected tumor samples and three human bile duct cancer cell lines all showed positive expression of Ang-1, 2 and Tie-2 mRNAs. High expressions of Ang-1, 2 and Tie-2 in human extrahepatic bile duct carcinoma cells suggested that Ang-Tie system may be involved in the progression of human bile duct cancer.