A total of 362 bile samples from 104 patients with evidence of biliary tract obstruction were submitted for diagnostic cytology from January, 1989 to April, 1991. The patients were classified based on the obstructive cause, and the cytologic results were reviewed. 298 of the specimens were from patients with intrabiliary malignant structure, and 17 were from patients with extrabiliary malignant compression or benign biliary obstruction. Bile cytology was positive for carcinoma in 42 samples from patients with intrabiliary malignant stricture, and the diagnostic sensitivity was 14%. There were no false positive cases. We concluded that the cause of low sensitivity was degenerative change of cell due to prolonged sampling time. What is noteworthy was the high prevalence of Clonorchis sinensis eggs, being detected in 25 patients with intrabiliary malignancy, supporting the association between clonorchiasis and biliary tree malignancy.