To assess relationships between increases in triceps skin-fold thickness (TRSF) and changes in levels of serum lipids and lipoproteins in early life, a biracial sample of 1,598 five to 12 year olds were reexamined five years after an initial examination. Significant positive correlations, controlled for age, were observed between changes in TRSF and changes in levels of serum total cholesterol, serum triglycerides, and low- and very low—density lipoprotein cholesterol. Inverse associations between changes in TRSF and high-density lipoprotein cholesterol were weaker, but also statistically significant. Although females showed the largest increases in TRSF, most associations were stronger in males. Increases in estimated percentage body fat and ponderal index (kilograms per cubic meter) were highly associated with changes in TRSF, but showed slightly different associations with the serum lipids and lipoproteins. Results show that increases in obesity in youth are accompanied by an increasingly atherogenic lipoprotein profile.