Screening for pancreatic cancer was carried out by serum pancreatic oncofetal antigen (POA) tests in 440 out-patients with abdominal complaints, with concomitant assay of carcinoembryonic antigen, alpha-fetoprotein and ferritin. POA was positive in 13 patients, of whom 3 cases of pancreatic cancer, and 4 of other malignant diseases were diagnosed while the remaining 6 were non-malignant. Of these out-patients, 5 cases were finally diagnosed as having pancreatic cancer by further examinations. Of these 5 patients, POA was negative in 2, of whom one was positive for CEA and AFP. Accordingly, when POA test was applied concomitantly with the other 3 marker tests, the detection rate of pancreatic cancer was elevated to 4/5. Twenty-three patients were found to have malignant diseases and 20 of them were positive for at least one of the 4 markers tested. These results suggest that serum POA assay is useful for screening the pancreatic cancer, especially when the other tumor markers are assayed concomitantly.