Ultrasonography of pancreas has been already estabilished to be a effective method in the evalustion of pancreatic mass lesion. In addition to ultrasonography, ultrasonoguided percutaneous fine needle aspiration biopsy of pancreatic mass has been known to be a safe method of obtaining tissue diagnosis in patients with pancreatic cancer without operation. From March, 1984 to June, 1986 ultrasonography and ultrasonoguided percutaneous fine needle aspiration biospsy were performed in 40 patients who had been finally diagnosed as pancreatic cancer at the Department of Radiology, Yonsei Univeristy College of Medicine. The results were summarized as follows: In ultrasonographi findings of pancreatic cancer, (1) The location of pancreatic mass is 19 cases in head , 3 in head and body, 7 in body, 4 in body and tail, 5 in tail and 2 diffuse type. (2) The size of tumor ranged under 2 cm in 2 cases, between 21 -4 cm in 21 between 4.1-6 cm in 13 and over 6 cm in 4 cases. (3) The other u traosnographic findings were 6 cases common bile duct dilatation, 4 pancreatic duct dilatation, 10 peripancreatic node enlargements, 16 liver metastasis and 3 stomach involvement . In ultrasonoguided percutaneous fine needle aspiration biopsy of pancreatic cancer, (4) The cytologic diagnosis were positive malignant cell in 31 cases(77.5%), highly suspicious malignant cell, but inconclusive in 3(7.5%), negative malignant cell in 2(5.0%) and material insufficiency in 4 cases(10%) (5) No significant complication during or after procedure was found.