Despite new diagnostic methods, including novel laboratory parameters and imaging techniques, and growing knowledge on pathogenesis of acute pancreatitis, early assessment of severity remains the main factor influencing prognosis in the disease. The aim of the study was the evaluation of diagnostic accuracy of interleukins (IL): 6 and 18 and acute phase proteins: C-reactive protein (CRP) and serum amyloid A (SAA), together with Glasgow prognostic score during first 48 hours after diagnosing acute pancreatitis in a group of 40 patients treated in the I-st Department of General and Gastrointestinal Surgery University Hospital in Cracow. All the studied inflammatory markers were significantly higher in patients with moderate and severe acute pancreatitis versus patients with mild form of the disease on the first 48 hours of the disease. Expanding Glasgow score with IL-6, IL-18, SAA or CRP determinations resulted in better accuracy for diagnosing severe clinical course of acute pancreatitis.