Exploration of biliary obstruction may involve many imaging methods and a large number of people. Radiologists, hepato-gastro-enterologists and surgeons may examine using ultrasound, CT, MRI, endoscopic ultrasonography, and percutaneous, intraoperative or endoscopic retrograde cholangiography. Interpreting radiological examinations and choosing an optimal strategy can be difficult. The aim of this paper is therefore: to explain how to explore a clinical and laboratory picture of biliary obstruction using imaging, by presenting its main causes, the methods of exploring them and their radiological signs; to suggest suitable exploration strategies; and to illustrate some of the traps that can make it difficult to diagnose the cause of the obstruction.