BackgroundType III choledochal cysts (CCs) are the rarest and least well-characterized of the five variants of biliary cysts. Only a few relevant studies have been conducted and a gold standard treatment for type III CCs is still lacking because of their scarcity. An unusual case of type III CC with choledochocele at the end of the distal common bile duct (CBD) with no bulging of the duodenum is presented here.Case presentationA 61-year-old woman presented to our department with repeated upper abdominal pain for one year. Laboratory examination revealed abnormal liver function and a slight increase in the white blood cell (WBC) count and proportion of neutrophils. In an MRCP of the patient, the distal CBD was found to have a cystic structure indicative of a type III CC. Endoscopic retrograde cholangiopancreatograpy (ERCP) revealed cystic findings compatible with Todani type III CCs. However, duodenoscopy did not show a bulge in the duodenum so laparoscopic cholecystectomy and Roux-en-Y hepaticojejunostomy were performed. In her 6-month follow-up, the patient reported that recovery from the operation was uneventful.ConclusionsERCP has become the gold standard for diagnosing type III CCs. Type III CCs can be treated minimally invasively with laparoscopic cholecystectomy and Roux-en-Y hepaticojejunostomy.