To examine the effects of dietary fat on the levels of lead in the blood, 34-40-d-old male mice were fed normal or high-fat diets along with distilled water for an initial 48-h exposure period. Following this session, subjects from each diet condition were administered either 0, 0.075, or 0.5% lead acetate through the drinking water during the next 48 h along with their respective diets. Atomic absorption was used to analyze blood-lead levels. At each concentration of lead, the high-fat diet increased the blood lead content over subjects fed the control diet. The highest blood lead levels were found in the 0.5% lead acetate, high-fat diet condition. The importance of nutritional considerations in understanding lead toxicity is discussed.