The efficacy of arteriographic triage of patients who sustained renal trauma into two groups, one optimally handled by early surgical intervention and one in whom conservative management guarantees maximal preservation of renal parenchyma, is discussed, based on a study of 190 patients. A substantial increase in the number of patients managed conservatively (73%) is attributable to use of arteriographic selection criteria. A very low rate of complications (2%) appears to substantiate the validity of the criteria on which the selection was based. Similarly, arteriographic criteria made possible substitution of hemi- or partial nephrectomy in almost 42% of patients who would otherwise have been treated by nephrectomy. A very low rate of complications resultant from this procedure justifies its use in these cases. The very low mortality rate (1.6%) of the present series suggests a bonus contribution of arteriography toward the management of associated intra-abdominal injuries. The safety of angiography and the now general availability of angiographic facilities and skilled personnel on a round-the-clock basis, and the policy-determining information derived from these studies, recommend widespread deployment of this method for the assessment of renal injury.