Abstract Fourteen adults who presented with choledochal cysts were studied. Symptoms in most cases were non-specific, which resulted in delayed diagnosis. Associated extracystic hepatobiliary disease occurred in 11 patients, including two with cholangiocarcinoma. Nine patients underwent total cyst excision (eight Todani classification type I and one type II), while four with type IVa cysts had excision of the extrahepatic cyst component. There were no surgical deaths. One patient with metastases was treated conservatively. Median follow-up was 6·5 years. Two of three patients who developed anastomotic strictures underwent successful revision surgery, while one with secondary sclerosing cholangitis developed biliary cirrhosis and died from hepatic failure after 8 years. Both patients with cholangiocarcinoma have died. Ten survivors are well and one patient was lost to follow-up. This study highlights the complexity of choledochal cysts in adults and emphasizes the need for earlier diagnosis and treatment. Cyst excision should be performed where possible, with reconstruction modified to deal with the cyst type as well as associated hepatobiliary pathology.