The prognostic value of the novel tumour marker CA 242 was studied in 175 patients with pancreatic cancer and the results were compared with those of CA 19-9. Preoperative serum levels of CA 242 and CA 19-9 were determined by commercially available assays. Patients were classified according to UICC TNM-stage, and divided into three groups of resectable, non-resectable and advanced disease. The lowest cut-off levels that divided patients into groups with significant difference in survival were calculated. Patients with resectable disease and preoperative CA 242 below 25 U/ml had a significantly better prognosis than those with a higher level (p < 0.05). The corresponding cut-off values were 100 U/ml in non-resectable (p < 0.05) and 3500 U/ml in advanced disease (p < 0.05). It is noteworthy that the overall survival rate of patients who underwent resection for cure, but had a high preoperative CA 242 level, approached that of patients with non-resectable disease. In multivariate analysis, only resectability (p < 0.0001) and preoperative serum CA 242 level (p = 0.01) were independent prognostic factors. If TNM-stage was used instead of resectability, the results were similar (stage p < 0.0001, CA 242 p = 0.006). When CA 242 was excluded from the model, preoperative serum CA 19-9 level approached the borderline of significance as an independent prognostic factor (p = 0.07). In conclusion, the preoperative serum level of the novel tumour marker CA 242 is an independent prognostic factor in pancreatic cancer. CA 242 yielded more prognostic information than CA 19-9.