Groove pancreatitis is a special form of chronic pancreatitis in which scarring is found mainly in the groove between the pancreatic head, duodenum, and common bile duct. Preoperative differentiation between groove pancreatitis and pancreatic cancer is difficult. Here we report one case of segmental groove pancreatitis diagnosed by clinical and radiological features. The patient was a 46-year old man with severe abdominal pain, weight loss, and a long history of alcohol abuse. Computed tomography revealed swelling of the pancreatic head and a heterogeneously enhanced low-density lesion in the groove. MR images revealed a mass in the groove that had a low signal on T1-weighted images and a low signal relative to the pancreatic head on T2-weighted images. T1-weighted images on dynamic study showed the medial wall thickening of descending duodenum, several small cysts in the groove and thickened duodenal wall. The patient has been under conservative treatment for 2 months and his severe abdominal pain has improved.