As the spectrum of pancreatic cysts evolves, sped by the increasing utilization of CT scanning, it becomes apparent that the surgeon must gain information preoperatively about the family history, as well as the personal history of the patient. The presence of cysts in the liver or kidney should be sought. The relation of the lesion to the duodenum and biliary tract needs to be defined. The possibility that the "cyst" represents necrosis of a primary adenocarcinoma of the pancreatic duct should be considered prior to laparotomy. At the time of operation, biopsy of the cyst wall and frozen-section study are fundamental to a decision whether resection or drainage is the treatment of choice. Resection is generally the treatment of the cystic neoplasms, drainage the treatment of pseudocysts. The failure of the surgeon to distinguish between the two groups may be catastrophic. The true cysts and cystic neoplasms of the pancreas are rare lesions. The clinical and radiologic characteristics, the pathologic features, and the natural history of these lesions are not fully documented. Therefore, when they are encountered, the clinician who will carefully document their characteristics can make a contribution to our knowledge.