As an imaging modality, angioscopy provides a simple method for the careful evaluation and treatment of the lumen of native vessels and bypass grafts. When used as a diagnostic study, angioscopy can provide more accurate information regarding the flow surface than conventional tests, such as angiography or duplex imaging. It can significantly enhance the ability of the surgeon to detect flow surface problems. With the recent advance in endovascular tools, angioscopically guided luminal intervention has become an increasingly useful approach to many vascular problems. More precise treatment of endoluminal abnormalities and a reduction in incision length and soft-tissue dissection can result in decreased patient morbidity and extended patient benefit.