We report a case of pancreatic acinar cell carcinoma. This rare tumor originating in pancreatic acinar cells often occurs at the pancreatic head. The cytology shows typical tubular and/or rosette-like patterns of cells with relatively monotonous oval nuclei resembling pancreatic acinar cells. It may be very difficult to diagnose precisely due to its rarity and to the existence of similar pancreas tumors. A precise diagnosis would be possible if specific tumor features and diagnostic points were better known.