To evaluate the safety and efficacy of cystoduodenostomy, the cases of 117 patients operated on for pancreatic pseudocysts during the last 14 years have been reviewed. Eleven patients were treated with cystoduodenostomy. They included ten men and one woman whose ages ranged from 26 to 56 years (mean 41 years). The etiology of pancreatitis was alcohol abuse in nine patients, alcohol abuse and gallstones in one, and trauma in one. Three patients had another cyst located within the body or tail of the pancreas which was identified preoperatively by ultrasound. Each patient underwent transduodenal cystoduodenostomy and three had a concomitant cystogastrostomy for a second pseudocyst. There was no operative mortality. Morbidity included postoperative pancreatitis in one patient, a wound infection and pancreatic fistula in one, and excessive bleeding from the cyst in one. There were no injuries to the common bile duct. Upon follow-up, which ranges from 6 months to 8 years, none of the patients has had a persistent or recurrent pseudocyst. This has been confirmed by ultrasound or computerized tomography (CT scan) in nine patients. Transduodenal cystoduodenostomy is a safe, reliable means of internal drainage for mature pseudocysts that are located in the head of the pancreas adjacent to the duodenum. Preoperative evaluation of the pancreas to rule out multiple pseudocysts and intraoperative care to avoid injury to the common bile duct are important factors in obtaining these good results.