Autopsy findings of pre-atherosclerotic changes in the coronaries and other arteries of young soldiers killed in action in the Korean war stimulated studies on the mechanisms that regulate the development of atherosclerosis. The data confirmed that vascular changes obviously begin developing much earlier than the manifestation of clinical symptoms, and numerous risk factors for atherosclerosis have been firmly identified. The mechanisms consist of the effects of numerous poorly characterized genes and a complex mixture of environmental factors, dominated by factors associated with nutrition. Observational and epidemiological studies also showed that the pathogenesis is not restricted to the postnatal period. The nutrition of the fetus during the 40 weeks of pregnancy may also play an important role both directly and by determining metabolism in the individual more widely than was previously believed. At the same time, several studies suggested that biochemical predictors of atherosclerosis, e.g. a high concentration of serum LDL cholesterol, a low concentration of serum HDL cholesterol and other lipid and lipoprotein abnormalities, may already in early infancy and childhood predict values later in life quite well. We now review recent studies that deal with the effects of fetal and childhood nutrition on serum lipid values, and discuss the likelihood that clinically meaningful changes of atherosclerosis may appear earlier than expected.