Renal cortical studies were performed in 19 children with renal transplants. There were 10 normal studies and 9 abnormal studies, 8 of which showed multiple large focal peripheral cortical defects. The following factors showed a positive correlation: (a) the ischemia time of the transplant kidney was significantly shorter in patients with normal studies; (b) cadaver grafts were more likely to have abnormal scan appearances than living related donor grafts; and (c) in four of the five patients with double renal arteries, the scans were abnormal in multiple sites. A possible pathophysiologic mechanism to explain these scan appearances is asymptomatic segmental graft infarction secondary to progressive vascular disease. These infarcts may be a long-term sequela of ischemic insult at the time of or prior to the insertion of the renal allograft.