Enzyme immunoassay was used to study blood levels of CA-19-9, cancerous embryonal antigen, and alpha-fetoprotein in blood donors (n = 33), patients with chronic pancreatitis (n = 35), those with pancreatic carcinoma with metastases (n = 28), and without them (n = 21). A differential diagnosis was found to be made between healthy individuals and patients with chronic pancreatitis and those with pancreatic carcinoma via determination of the above tumour markers. The presence of hepatic metastases of pancreatic carcinoma may be suspected if the blood levels of the cancerous embryonal antigen and CA-19-9 are over 15 ng/ml and over 600 U/ml. The level of alpha-fetoprotein was higher only in 14.3% of pancreatic carcinoma patients with hepatic metastases. A comprehensive examination of the levels of all three tumor markers allows one to differentiate pancreatic carcinoma and chronic pancreatitis and to determine whether a patient with pancreatic carcinoma is operable.