Objective: To evaluate the manifestation of pancreatic head carcinoma andchronic pancreatitis of pancreatic head on magnetic resonance (MR) imaging and to determine whetherMR imaging can distinguish the two diseases. Methods: A retrospective review of MR findings wasperformed for 24 patients with pancreatic head carcinoma and 3 patients with chronic pancreatitis ofpancreatic head. SE T1WI and FSE T2WI sequences with and without fat suppression were performed onall 27 cases. Enhanced SE T1WI with fat suppression was performed on 8 patients with carcinomas and3 patients with pancreatitis, respectively. When dilatation of the pancreatic and/or biliary ductswas noted on T2WI sequence, MRCP were performed on 23 patients with carcinoma and 1 patient withpancreatitis, respectively. Results: Cases of carcinoma presented hypointensity (n=8) or mildhypointensity (n=16) on conventional SE T1WI, hy-perintensity (n=8), mild hyperintensity (n=5),isointensity (n=10) or hypointensity (n=1) on conventional FSE T2WI,hyperintensity (n=11),isointensity (n=11) or mild hypointensity (n=2) on FSE T2WI with fat suppression, and hypointensity(n=24) on fat-suppressed SE T1WI. MRCP demonstrated typical 'double duct sign' and abruptinterruption at distal segment of dilated common bile duct. All 8 patients with carcinoma showedlittle enhancement. All 3 patients with chronic pancreatitis showed mild hypointensity oriosintensity on conventional SE T1WI and hyperintensity on conventional FSE T2WI sequences,respectively. Two patients showed isointensity and mild hyperintensity on fat-suppressed SE T1WI andFSE T2WI sequences, respectively. The remaining patient showed hypointensity and heterogeneousintensity on fat-suppressed SE T1WI and FSE T2WI sequences respectively and a mild dilated commonbiliary duct with irregularly dilated proximal pancreatic duct on MRCP. All 3 patients with chronicpancreatitis showed various enhancements. Conclusion: Both pancreatic head carcinoma and chronicpancreatitis show various signals on various sequences and abn