Atherosclerosis begins in childhood with fatty streaks, which progress seamlessly to fibrous plaques in adulthood. These plaques, in turn, might rupture and cause thrombotic arterial occlusion and ischemic damage to vital organs. The earliest stages and progression of atherosclerosis in youth are influenced by the same major established risk factors for this condition in adults-dyslipidemia, hypertension, smoking, obesity, and diabetes mellitus. Controlling these risk factors at any age is beneficial, but the earlier primary prevention begins, the better the result. As recommended by the American Academy of Pediatrics, pediatricians should support both control and prevention of these risk factors in children via lifestyle modification. Drug treatment can be used to supplement lifestyle modification in the few cases of children with genetic dyslipidemias who do not respond to diet changes. Ultimately, however, effective prevention of adult disease requires a massive cultural change.