Background and Study Aims: The clinical importance of magnetic resonance cholangiopancreatography (MRCP) as a noninvasive diagnostic modality for investigation of the biliary tree and pancreatic duct system is under debate. Using endoscopic retrograde cholangiopancreatography (ERCP) as the gold standard, this study determined in a prospective, blinded fashion the sensitivity and further statistic values of MRCP findings for evaluation of the biliary and pancreatic tract. Patients and Methods: Seventy-eight patients referred for ERCP were studied prospectively with MRCP and ERCP during a 12-month period. All images were interpreted on a blinded basis by two radiologists. Any dilations, strictures, and intraductal abnormalities were recorded and correlated with the clinical diagnoses. Results: MRCP images of diagnostic quality were obtained in 76 of the 78 patients (97 %). Magnetic resonance cholangiography (MRC) showed sensitivities (and positive predictive values) of 71 % (62 %) for recognition of normal bile ducts, 83 % (91 %) for recognition of dilation, 85 % (100 %) for recognition of strictures, 77 % (91 %) for correct stricture location, and 80 % (100 %) for diagnosing bile duct calculi. In addition, the sensitivity of MRC in classifying benign and malignant strictures was 50 % and 80 %, respectively. The statistical values (sensitivity and positive predictive value) for magnetic resonance pancreatography findings were determined for the recognition of normal pancreatic ducts (33 % and 50 %), recognition of dilation (62 % and 100 %), recognition of strictures (76 % and 87 %) and correct location (66 % and 100 %), diagnosis of benign strictures (87 % and 87 %) and malignant strictures (60 % and 75 %), and for diagnosing pancreatic duct stones (60 % and 100 %). Conclusions: MRCP is capable of providing diagnostic information equivalent to ERCP in many patients, and should be applied whenever established techniques provide no results, or inadequate results.