The aim of this study was to analyze osteopontin (OPN) concentrations in patients with acute pancreatitis (AP) and its suitability for diagnosis and prediction of severity during the first 3 days from admission to hospital. The study group consisted of 40 patients admitted and hospitalized at I-st and II-nd Depatments of Surgery Jagiellonian University Collegium Medicum in Krakow. All laboratory tests necessary for diagnosis and monitoring of patients were performed in the Diagnostic Dept. of University Hospital, other immunochemistry parameters were assesed in the Diagnostic Dept. of Clinical Biochemistry Jagiellonian University using ELISA kits. The concentrations of OPN in severe acute pancreatitis were significantly higher than in patients with mild form of disease in the whole observation period. Simultaneously, we observed that increased in OPN concentrations in consecutive days of AP may be helpful in prediction of severity and compilations during AP.