Angioscopy is a useful investigation in patients referred for vascular surgery. The material has been improved over the last few years to make available angioscopes with external diameters ranging from 0.55 to 3.2 mm. The angioscopes are either rigid, composed of two groups of fibre optics (image and light transmission) or orientable and more complex. Both systems may carry operating channels. The angioscopy may be performed peroperatively or percutaneously. Other essential equipment includes catheter guides, balloon catheters, counterpulsation balloons or perfusion pumps. This investigation is used for diagnostic evaluation but when used peroperatively it may also help guide therapeutic intervention. Angioscopy is complementary to ultrasonic and radiological methods of vessel imaging.