Background: Childhood cancer survivors are at higher risk of morbidity and mortality from cardiovascular disease compared with the general population.Methods: Eight thousand five hundred ninety-nine survivors (52% male) and 2,936 siblings (46% male) from the Childhood Cancer Survivor Study, a retrospectively ascertained, prospectively followed study of persons who survived 5 years after childhood cancer diagnosed from 1970 to 1986, were evaluated for body mass index of ≥30 kg/m 2 based on self-reported heights and weights and self-reported use of medications for