Childhood obesity is a growing concern for practitioners and researchers. In addition to obesity being a risk factor for cardiovascular disease, children classified as obese are more likely to demonstrate other risk factors associated with cardiovascular disease. Furthermore, children classified as obese are more likely to be victims of bullying and discrimination. This dissertation tested a dynamic cascade model of the development of childhood obesity. It was hypothesized that externalizing behaviors and internalizing problems would lead to increased body mass index. This model was tested in Mplus v7 (Muthén & Muthén, 1998) using data from the NICHD Study of Early Child Care. This dissertation used parent report of externalizing behaviors and internalizing behaviors, teacher report of externalizing behaviors, and body mass index to examine several different ways in which developmental psychopathology related to childhood obesity. The results suggested that body mass index predicts the development of internalizing problems in late childhood. However, externalizing behaviors were not directly or indirectly associated with body mass index. These findings suggested that the assessment of children with internalizing problems should include an assessment of their weight and weight related concerns.