We found significant evidence that the more a mother knows about health and nutrition the better is the overall quality of her children’s diet, for preschoolers more so than older children. We also found that a mother’s years of schooling, smoking status, race, and ethnicity influence her children’s diet. Our results imply that health and nutrition education may be more effective if targeted toward mothers with young children but directly toward school-age children. We assessed overall diet quality using the Healthy Eating Index, the U.S. Department of Agriculture’s instrument for measuring overall diet quality incorporating 10 recommended nutritional guidelines.