Conventional angiography allows a global view of regional vascular anatomy but precise information can only be deduced indirectly using contrast medium. The use of the three-dimensional picture of angioscopy, however, allows a direct evaluation of the vascular system. In order to extend our experiences with angioscopy, we employed a new micro-cardio-angioscopic system which consists of four components: a CCD color camera (360,000 pixels); a highly flexible optical probe which can be resterilised (1.4-0.6 mm diameter) incorporating 10,600-6,000 glass fibers, with a viewing angle of 140 degrees, 70 degrees, and 50 degrees and a focusing system that allows a distance from 2 mm to infinity; a high power light source and an insertion catheter with inflatable balloon. Using a known technique (intermittent blood-flow blockage and continual rinsing with NaCl solution), 36 cases involving 27 patients were examined before and after desobliteration of the femoral artery. In 88% of the cases it was possible to control the result of the intervention by angioscopy. Smaller intimal lips, the thrombotic wall, and intimal ruptures were clearly visible. Quantification of the stenoses was also successful in 88% of the cases, and in 8 patients the angioscopic findings deviated from the conventional angiogram. In 14% of the cases, angioscopic examination of the recanalisation result showed that thrombolytic therapy was necessary. Angioscopy offers the possibility of qualitative vascular diagnosis. It is a valuable addition to angiography.