Reference is made to the world literature and personal experience acquired at the Digestive Endoscopy Centre, 3rd Surgical Clinic, in an assessment of the value of PRC and TPC in the diagnosis of hepatobiliary disease. PRC is ideally employed when conventional examinations have been inconclusive, and especially in icterus, when technical reasons have prevented their execution. TPC may be required in jaundice when PRC has proved impracticable, or if the data it offers concerning the state of the bile ducts upstream from an obstruction are insufficient for the planning of suitable surgical management.