• We describe 8 children among a group of 40 in whom growth failure was associated with unsupervised dietary treatment of hypercholesterolemia. In 3 children, nutritional dwarfing ensued, and in 5, weight loss or insufficient weight gain occurred. Children with growth failure consumed significantly less energy and zinc than those children growing well. The dietary intakes of the 3 children with nutritional dwarfing were the most markedly deficient in total energy, fat, and micronutrients. These data suggest that the diagnosis and dietary treatment of hypercholesterolemia have potentially adverse consequences. Overzealous application of a low-fat, low-cholesterol diet may lead to growth failure due to inadequate intake of energy, vitamins, and minerals. Careful monitoring of children receiving modified fat and cholesterol intakes for hypercholesterolemia treatment is mandatory to ensure adequate nutrition for normal growth and development.