During the period 1963 to 1988, we treated 45 patients with cystic neoplasms of the pancreas. The patients were divided into group 1, which included 26 patients treated between 1963 and 1983, and group 2, which included 19 patients treated between 1984 and 1988. The rate of resection for cystadenoma was 67% for group 1 (n = 15) and 100% for group 2 (n = 11). The operative mortality rate was 0% for both groups. Pathologically, 17 patients (69%) had serous cystadenoma and nine (31%) mucinous adenoma. Except for 5 of the 15 patients from group 1 who died of other causes, all patients are healthy. The resection rate for cystadenocarcinoma was 36% for group 1 (n = 11) and 100% for group 2 (n = 8). In 2 patients from group 1 and 1 patient from group 2, the tumors had been diagnosed previously as benign by operative biopsy of the cyst wall. There was no operative mortality in either group. Cystic neoplasm was suspected from the results of ultrasonography and computed tomography in 70% of the patients in group 2. In 2 patients (25%), the preoperative diagnosis of pseudocyst associated with chronic pancreatitis was made. Adenocarcinoma was diagnosed in 3 patients by needle biopsy and cytologic examination of pancreatic juice. Eighty-two percent (9 patients) of group 1 died of recurrent carcinoma; 2 patients were alive without disease at 5 and 8 years. Thirty-eight percent (3 patients) of patients in group 2 died of recurrent carcinoma, two patients died of other causes, and 3 patients are still alive.(ABSTRACT TRUNCATED AT 250 WORDS)