For evaluating the diagnostic rate of serum CA19-9 and carcinoembryonic antigen (CEA) in pancreatic malignancies and pancreatitis, 22 patients with pancreatic malignancy, 27 patients with acute pancreatitis and 7 patients with chronic pancreatitis were included in this prospective study. The normal values of CEA and CA19-9 were 2.0 ng/ml and 36 U/ml respectively in 10 healthy males and 11 healthy females. The positive rates of CEA (greater than 2.5 ng/ml) in pancreatic malignancy, acute pancreatitis and chronic pancreatitis were 50%, 47% and 38%, respectively. On the other hand, the positive rates of CA19-9 (greater than 37U/ml) in pancreatic malignancy, acute pancreatitis and chronic pancreatitis were 82%, 26% and 23%, respectively. In diagnosis of pancreatic malignancy, the positive rate of CA19-9 is higher than that of CEA (82% vs 50%), and CA19-9 has a sensitivity significantly higher in differentiating from pancreatitis than CEA. In 7 cases of pancreatic malignancy with metastasis (liver or peritoneum), all had abnormally high serum CA19-9 (greater than 195 U/ml), 6 of 7 had CA19-9 levels over 1000 U/ml. In the view of CEA, 6 of 7 had serum CEA over 5 ng/ml, one patient with peritoneal metastasis had normal CEA level. In this study, we conclude that the diagnostic rate of CA19-9 in pancreatic malignancies is better than that of CEA.