The occurrence of iatrogenic arterial injury secondary to catheterization for angiographic studies has been well documented in the literature for over a decade. It has been well established that patients should be carefully evaluated post-catheterization and if absence of the pulse distal to the arteriotomy site is discovered, most should undergo exploration for identification and correction of the problem. Between 0.3 and 24% of patients undergoing brachial artery catheterization have been found to have a diminished or absent radial pulse after the procedure. In the vast majority of cases the problem has been solved by local exploration of the arteriotomy site. However, in a small but definite number of cases late thrombotic complications have become manifest, and in two cases reported in 1981 and in the case report to follow, thrombotic complications have become manifest months later, secondary to injury well proximal to the arteriotomy site.