OBJECTIVE: The safety and efficacy of endoscopic retrograde cholangiopancreatography (ERCP) in the evaluation and management of biliary tract complications after orthotopic liver transplantation (OLT) have been previously demonstrated. However, the role of ERCP in evaluating asymptomatic OLT patients with abnormal liver enzymes with a previously normal biliary tree remains poorly defined. We sought to assess the utility of ERCP in this subset of patients. METHODS: A retrospective analysis of-asymptomatic OLT patients with abnormal liver enzymes evaluated by ERCP was undertaken. In addition to ERCP, all these patients had a diagnostic abdominal Doppler ultrasound, and a percutaneous liver biopsy. All patients had choledochocholedochostomy at the time of transplant and normal T-tube cholangiograms 3 months postoperatively. A radiologist, blinded to clinical findings, interpreted the ultrasound as normal, biliary dilation, or vascular abnormalities. The same radiologist interpreted ERCP findings. A pathologist, blinded to clinical findings, graded liver biopsies as normal, diagnostic, or abnormal but nondiagnostic. RESULTS: Twenty-two patients underwent 23 ERCPs. Twenty-two of the 23 ERCPs were normal (96%), and one abnormal ERCP finding did not explain the liver enzyme abnormality. Liver biopsy was diagnostic in 13 of 22 (57%) and in each case the ERCP was normal. The remaining 10 liver biopsies were abnormal but nondiagnostic. Ultrasound was abnormal in five of 22 cases, but in the three cases suggesting biliary dilation, the ERCP was interpreted as normal. CONCLUSION: Routine use of ERCP in evaluation of asymptomatic OLT patients with liver function test abnormalities and normal cholangiograms at 3 months was not diagnostically useful. In this subset of patients, liver biopsy was usually abnormal and frequently diagnostic and should be the initial invasive diagnostic procedure.