The following study comprises 116 patients (77 men, 39 women) admitted to the Second Surgical Clinic of the Pirogov MBALSM (Multiprofiled Hospital for Active Treatment in Emergency Medicine) within the period from June 2000 till November 2003. Patients were divided into three groups: patients presented with alcohol induced acute pancreatitis (AAP) (n=30); patients suffering from biliary acute pancreatitis (ABP) (n=58); and patients having an idiopathic form of acute pancreatitis (n=28). Till the 24th hour after admission to the clinic, we evaluated serum amylase, aspartate aminotransferase (AST), alanin aminotransferase (ALT), alkaline phosphatase (ALP), gamma-glutamyl transferase (GGT), total bilirubin, and the cytometric indicator - mean corpuscular volume (MCV). These laboratory findings were analyzed with the help of routine clinical laboratory methods, and the results were elaborated with the software package SPSS. In patients suffering from ABP, we evaluated higher median levels of serum amylase (P=0.047), AST (P=0.019), and ALT (P=0.001), in comparison to the group suffering from AAP who presented with higher levels of GGT (P=0.128) and particularly MCV (P=0.015). As a whole, serum amylase, AST and particularly ALT continue to play a major role in diagnostic and differential-diagnostic assessment of AP. The role of the hematological parameter MCV is similar. The enzyme ALT is capable to distinguish formations of microlithiasis in patients suffering from acute idiopathic pancreatitis where it is impossible to identify the underlying biliary cause by routine imaging diagnostic procedures. .