Brunner's Gland Adenoma is a very rarely seen benign tumor of duodenum. While it generally leads to obstruction and bleeding complaints, it may very rarely occur by mimicking a pancreatic tumor. A 48 years old male patient admitted to the gastroenterology clinic due to the epigastric pain spreading dorsally. No significant feature is present in his clinical history. A lesion containing cystic solid components in the size of 30x40 mm was detected in the head of pancreas as a result of the abdominal tomography. In the light of these findings, pancreaticoduodenectomy is applied to the patient. It is observed that tumor is in submucosal location and widely invaded the pancreatic head. In the histopathological examination, Brunner's Gland Adenoma is reported in pancreatic head localization. In this manuscript a case of Brunner's gland adenoma diagnosed by performing pancreaticoduodenectomy due to the mass in the head of the pancreas is presented.