Liver functional tests due to inflammatory process which induced by cholecystitis might changed and some clinicians suggested that these changes might help us to stone prediction in common bile ducts and decrease hazards of performing ERCP and other invasive procedures. Present study was performed for assessment of role of liver functional test in diagnosis of common bile duct stone in patients with cholecystitis and help in their management. Present prospective study was performed between April 2010 and March 2011 on 350 patients who come to our hospital with cholecystitis or biliary colic diagnosis. Patients with cholesistitis diagnosis were underwent operation for removing gall bladder stone and retrograde cholangiopancreatography (ERCP) was performed for patients with suspicious to biliary colic and common bile duct (CBD) stones. Ultrasonography, Aspartate Aminotransferases (AST), Alanine Aminotransferases (ALT), Alkaline Phosphatase (ALP) and direct and total serum bilirubin were measured for all of participated patients. Mean of AST. ALT, ALP and total and direct bilirubin were had no significant differences between two study groups. In logistic regression analysis, after entering into the model only CBD diameter (OR: 20; P=0.00) and elevated serum level of ALT (OR: 2; P=0.04) were remained into the model and were known as independent predictor of cholelithiasis. Elevated level of liver enzymes had not main role in CBD diagnosis and ERCP had no to perform for suspicious CBD stone only with elevated liver enzyme and even with normal ultrasonography findings. Endosonography as non invasive procedure recommend for patients before ERCP.