The arterial pulse wave was recorded in 907 diabetic and 203 normal subjects between 10 and 19 years of age. The technique involves the application of a cuff about the finger and does not require intra-arterial puncture. A 73% prevalence of abnormalities was found in the arterial pulse wave of the diabetic children, none of whom had overt, clinical evidence of vascular disease. Only 7% of the nondiabetic children had arterial pulse wave abnormalities. The exact nature of the vascular abnormality reflected by the pulse wave is unknown. However, arterial pulse tracings would seem to provide a convenient and accurate means of evaluating early vascular disease before the onset of clinical symptoms. Studies are currently in progress to determine the clinical applicability of this procedure to large population groups.