Increased arterial stiffness is an independent predictor of cardiovascular disease and mortality in middle-aged and older adults. However, limited data are available regarding the relationship of arterial stiffness in young adults with risk factors measured in childhood, adulthood, or as a cumulative burden from childhood to adulthood. This aspect was examined in a sample of 835 black and white young adults (72% whites, 44% men) aged 24 to 44 years who had at least 4 measurements of traditional risk factors over an average follow-up period of 26.5 years since childhood. Brachial-ankle pulse wave velocity (baPWV) measured by a simple automatic oscillometric technique was used as an index of arterial stiffness. The cumulative burden of risk factors since childhood was measured as area under the curve divided by follow-up years. In young adults, the baPWV was higher in males versus females (P<0.001) and blacks versus whites (P<0.001). In multiple regression analyses, independent predictors of baPWV in young adults were systolic blood pressure in childhood; systolic blood pressure, high-density lipoprotein cholesterol, triglycerides, and smoking in adulthood; and cumulative burden of systolic blood pressure and triglycerides and duration of smoking years from childhood. Thus, systolic blood pressure beginning in childhood is a consistent predictor of arterial stiffness in free-living, asymptomatic young adults. These findings underscore the importance of childhood blood pressure in the evolution of arterial stiffness and the need for beginning preventive cardiology early in life.