The miniaturized diameters of endoscopes (miniendoscopes) allow percutaneous access for endoscopic visualization of the extrahepatic and intrahepatic biliary system. Practical aspects of different miniendoscopes in an experimental model are described. Clinically, fine caliber cholangioscopy is helpful in detection of retained biliary stones. Nevertheless, discrimination of benign and malignant stenosis remains difficult, and simultaneous intervention under endoscopic guidance is compromised by the low steerability of the instruments.