Introduction: Because of the inability to determine benign from malignant, many have recommended that all cystic lesions of the pancreas be resected. Recent studies however, have suggested that some patients may be safely followed as current imaging techniques have improved the ability to characterize these lesions. Methods: Inpatient and outpatient physician billing data was obtained, and patients evaluated between Jan 1995 and Dec 2000 with the ICD-9 diagnosis of pancreatic cyst (577.2) were reviewed. Patients presumed to have a pancreatic pseudocyst, intraductal papillary mucinous neoplasm, or cystic islet cell tumor were excluded. Patient, cyst, and treatment characteristics were recorded. Comparisons were made between patients who underwent non-operative and operative management. Patients managed non-operatively were typically followed with either high quality C.T. scanning, or M.R.C.P., on an annual or biannual basis. Results: Over the five year period, 209 patients were evaluated with the pre-treatment ICD-9 diagnosis of pancreatic cyst. Non-operative treatment was chosen for 138 patients (66%), and within this group the median radiographic follow-up was 31 months. The average initial cyst diameter was 2.5 cm (range 0.5 - 13.0), and the median change in cyst diameter during follow-up was 0 cm (range -1.5 - 4.0). Cyst growth warranting resection occurred in six patients (4%); however none of these patients had a malignant diagnosis. Operative treatment was chosen for 71 of the 209 patients (34%). A malignant diagnosis was found in five of the operative patients (5/71, 7%), and 39 patients (55%) had a serous cystadenoma. All five of the patients with a malignant cyst had septated cysts that were symptomatic, with an average cyst diameter of 7.0 cm (range 5.0 - 10.0). Differences between operative and non-operative groups are depicted in the table. Conclusions: Selected patients with cystic lesions of the pancreas may be safely followed radiographically. Selection criteria identified in this study (cyst size, solid component, septations, symptoms), and the utilization of new imaging techniques, allow the creation of logical treatment paradigms for these patients.