Aim: To determine how endoscopic ultrasound (EUS) is compared to magnetic resonance cholangiopancreatography (MRCP) in diagnosing cholelithiasis in acute biliary pancreatitis.Method: Five steps of evidence based medicine is conducted, they are: (1) Formulate the clinical question; (2) Search the evidence; (3) Appraise the study; (4) Apply the answer; (5) Assess the outcome. The search term in general is: (“cholelithiasis”) and (“EUS”) and (“MRCP”) and diagnosis.Results: We searched in Pubmed and Cochrane library. We excluded articles that do not focus on answering our clinical question. There is one systematic review that is capable of answering our clinical question.Conclusion: It can generally be concluded from this study that EUS and MRCP are useful techniques in the etiological diagnosis of acute pancreatitis of non-established cause. Endoscopic ultrasonography should be preferred for establishing a possible biliary etiology in patients who have not had a cholecystectomy.