The management of 23 patients treated for choledochal cysts at the Oregon Health Sciences University between 1969 and 1990 is reviewed. The median age was 27 years, with a range from 1 month to 90 years. Seventy-eight percent of patients presented with abdominal pain, and 35% were jaundiced. Three patients presented with cholangitis, two with cyst rupture, and one with recurrent pancreatitis. Nine patients had had previous biliary surgery. The diagnosis was made in all patients with ultrasound and/or cholangiography. Fifteen patients (65%) had type I cysts, 2 had a type II cyst, 5 (22%) had type III cysts, and 1 had a type IV cyst. Stones were present in four (17%) cysts, and all excised cysts were benign. Seventeen patients with type I and II choledochal cysts had complete cyst excision and choledochoenterostomy. Four of five patients with type III cysts had endoscopic cyst incision and drainage, while the fifth patient had transduodenal cyst excision and sphincteroplasty. The patient with a type IV cyst had extrahepatic cyst excision and choledochojejunostomy. There were no operative deaths. Two postoperative complications occurred: cholangitis and a prolonged ileus. All patients had resolution of their pain and jaundice. Two patients had late cholangitis. Cyst excision and choledochojejunostomy are the treatment of choice for types I and II choledochal cysts. Extrahepatic cyst excision and choledochojejunostomy may be adequate treatment for type IV cysts. Endoscopic incision and drainage is appropriate for selected patients with type III cysts.