The monoclonal antibody pyruvate kinase type tumor M2 (TUM2-PK) has been shown to have a high binding capacity to pancreatic cancer. In present study TUM2-PK serum levels were measured in pancreatic cancer and compared with the reference tumor markers CA19-9, CA50, CA72-4 and CEA. Overall 100 patients were included in this study, 64 patients had a histologically confirmed pancreatic carcinoma, 36 patients gastrointestinal cancer (stomach, colon), 666 healthy volunteers served as controls. Measurements were done by enzymimmunoassay. For the healthy blood donors a cut-off value of 22.5 U/ml was evaluated, which corresponds to 95% specificity. In patients with pancreatic cancer the sensitivities of TUM2-PK, CA19-9, CEA, CA72-4 and CA50 were 71%; 68%, 37%, 49% and 63.4% respectively. Linear regression analysis indicated that there was a positive correlation (r = 0.79). According to the results of our study TUM2-PK has comparable sensitivity but higher specificity than the reference tumor marker CA19-9.