We describe a case of gastric aberrant pancreas with acute pancreatitis. Barium meal examination, endoscopic examination and computed tomography of a 32-year-old man with abdominal pain revealed a submucosal tumor, about 3.5 cm in diameter, at the angulus of his stomach. Endoscopic ultrasonography revealed a hypoechoic mass with anechoic capillary areas. His serum amylase level was high at 262 IU/l. Laparoscopy-assisted local resection was carried out. The resected tumor revealed pancreatic tissue with extensive neutrophil infiltration in the gastric wall and fat necrosis in the subserosa. There are few cases of histologically proven acute pancreatitis in gastric aberrant pancreatic tissue.