This study investigated the relationship between obesity and mental health in preschool children, using data from the Longitudinal Study of Australian Children (LSAC). The paper reports that the differences in rates of mental health problems between preschoolers of different weights is relatively small. Obese girls had more peer problems and conduct problems than obese boys. When the control of sociodemograhic factors was used, the boys results showed very small differences between obese and nonoverweight boys. The paper concludes that a reduction in the negative social position of young children, has the potential to improve rates of mental health in overweight older children.