Intravascular ultrasound imaging of saphenous vein grafts may enhance the angiographic interpretation of results following transcatheter interventions. We used intravascular ultrasound to study 18 patients with stenotic vein grafts following balloon angioplasty, atherectomy, or stent placement. In real-time imaging the three-layer appearance was rarely seen, calcification was infrequent (11% of patients), and atheroma were usually mildly echogenic ("soft"). Despite excellent angiographic results (reduction in percent diameter stenosis from 90 ± 8% to 17 ± 8%) and concordant improvement in lumen area by ultrasound regardless of the intervention, there was usually significant retained atheroma at the treatment site. Following balloon angioplasty, ultrasound showed multiple superficial fissures and fractures without discrete dissections. Atherectomy caused a smooth lumen surface without deep dissections or resections, but significant retained atheroma was observed with each one of the atherectomy procedures. Endovascular stents were concentric in the vein with reflective struts above compressed atheroma and an outer echogenic adventitia. Stent expansion was asymmetric axially and longitudinally and evidence of stent recoil was present. Thus intravascular ultrasound may be an important adjunct to angiography in characterizing postintervention results in saphenous vein grafts.