Cholangiocarcinoma may arise in the small bile ducts within the liver or in the large ducts in the hilum or the extrahepatic biliary tree. Curative surgical excision is being increasingly attempted for tumours at all sites and the best results are achieved with cancer at the lower end of the common bile duct. Palliative bypass surgery to drain the biliary tree gives good symptomatic relief and may provide prolonged survival because these tumours are often slow growing. Radiotherapy deserves more extensive trials since about 50 per cent of patients derive benefit. The results of treatment with cytotoxic drugs are so far disappointing.