The experience with 131 patients with 157 pseudocysts is reported. One hundred and twenty patients with 146 pseudocysts underwent 165 operations. There were ten operative deaths (8.3%) three of which were not attributable to the pseudocyst or its operative management. Sixteen patients died six months to 14 years after operation. Deaths in six of the 16 patients were in part attributable to pancreatitis or complications of pseudocyst management. The operative mortality was highest in patients undergoing incision and drainage and cystoduo-denostomy. Other factors influencing mortality unfavorably included postoperative gastrointestinal hemorrhage from a pseudocyst; rupture or flstulization of the cyst into the gastrointestinal tract if associated with hemorrhage, and evidence of common duct obstruction, or the location of cysts in the head or uncinate process of the pancreas. Visceral angiography should be performed on all patients with pseudocysts. The risk of massive gastrointestinal or intra-abdominal hemorrhage is highest in the 10% of patients having pscudoaneurysms associated with their pseudocysts. Incision and drainage of pseudocysts is associated with a high rate of recurrence of the cyst and continued pain. Incision and drainage should only be used if the cyst is infected, or the cyst wall is not mature enough to hold sutures. Cystogastrostomy and cystojejunostomy are the procedures of choice for mature cysts. The presence of a pseudo-aneurysm visualized on preoperative visceral angiography is an indication for an cxcisional operation as are the presence of multiple cysts, compression of the common duct or duodenum by the cyst, evidence of left sided portal hypertension, recurrent cysts or evidence of chronic pancreatitis.