Objectives: Acute pancreatitis is a inflammatory process of the pancreas which leads to endocrine and exocrine disturbances of pancreas. Although the disease process may be limited to pancreatic tissue, it also can involve peripancreatic tissue or more distant organ sites. For the treatment of the acute pancreatitis is very important to be able to predict outcome in the early stage of the disease. The aim of the study is to establish the prognostic value of cytokines as biochemistry markers and prognostic score systems in prediction of complications in acute pancreatitis with special regard to their clinical usefulness and test performance for stratifying severity and monitoring disease progression. Patients and Methods: The study was carried out in a group of 150 patients with acute pancreatitis, both sex (71 male and 79 female) admitted to Division of Gastroenterology, Department of Internal Medicine, Clinical Hospital Centre Rijeka. Concentration of cytokines and elastase were determined by enzyme-linked immunosorbent assay and C-reactive protein by immunoturbidimetry. Blood tests for the pro-inflammatory cytokines (IL-6, IL-8, sTNFr, IL-15, IL-17, IL-18) and antiinflammatory cytokine (IL-10), elastase as specific enzyme of pancreas and Creactive protein as dominant protein of acute phase of the illness, in patients with acute pancreatitis were performed. Blood tests for elastase and C-reactive protein were performed on 1st and and 3rd hospital days. We calculated prognostic score systems Ranson, APACHE II, APACHE III, SAPS and Balthasar as predictors of outcome of illness. Results: The serum concentration of IL-6, IL-8, IL-10 and sTNFr were significantly higher in patients with acute pancreatitis with complications of illness than those patients without complications. IL6, IL-8, IL-10 and sTNFr are sensitive and useful parametars for early prediction of the severity of acute pancreatitis. Serum concentration of IL-15 and IL-17 were not elevated in patients with acute pancreatitis, while serum concentration of IL-18 were elevated in patients with acute pancreatitis but without significant value in prediction of the severity of illness. The serum concentration of elastase and C-reactive protein measured on the third day of admission in hospital are useful for prediction of the severity of acute pancreatitis. Prognostic score systems Balthasar, Ranson and APACHE II are useful to assess severity of illness, while SAPS and APACHE III are not useful. Conclusion: Prognostic scoring systems has, without doubt, very important role in assessment of severity of acute pancreatitis, but they need further evaluation to achieve better, safer and earlier assessment of severity of illness. Combination with IL-6, IL-8, IL-10 and sTNFr, and with serum concentration of elastase and C-reactive protein third day of admission in hospital, evaluation of severity of acute pancreatitis will become more reliable.