Since its introduction, cholangioscopy has been used diagnostically and therapeutically. The working channel size has increased, permitting direct visualization for tissue sampling and to guide application of lithotripsy for difficult stones. Cholangioscopy utilizes endoscope and catheter-based systems. The application of slim gastroscopes for direct cholangioscopy provides better image resolution than conventional systems. Cholangioscopy has proven effective in the management of large biliary stones and for the diagnosis and exclusion of biliary tumors. Commercially available cholangioscopes are fiberoptic; those with digital video technology remain in a prototype development phase. This review covers available cholangioscope technologies, indications, technique, efficacy, and complications.