Acute pancreatitis (AP) exhibits high prevalence and high social and economic impact. It is mainly of biliary etiology in our setting. Endoscopic ultrasonography is not always available due to its high costs. Alanine aminotransferase (ALT) Ievels greater than 150 UI/1 have been related to biliary duct obstruction. Objective: to determine ALT features among our population to establish biliary etiology. Materials and Methods: a cross sectional study at Hospital de San José, Bogotá DC. The medica) records of all patients with AP from August 2010 to March 2012 were reviewed. Social, demographic, clinical, laboratory, imaging, intraoperative findings and etiologic diagnosis data were analyzed. Results: 106 patients were recruited, 67% females. An ROC analysis established that at ALT Ievels greater than 74 IU/1 there was greater sensibility and specificity than at ALT Ievels of 150 IU/1. The relation between greater than 74 UI/1 ALT levels with hyperbilirrubinemia, jaundice and ultrasonographic findings compatible with biliary etiology was found. Conclusion: there is statistically significant correlations between ALT Ievels greater than 74UI/I and biliary etiology (sensibility 89 %, specificity 71 %), p <0.001. Further studies comparing this diagnostic test with endoscopic ultrasonography are required.