This study investigated the association between child maltreatment and body mass index (BMI) using data from four waves (wave 2 in 2011 through 5 in 2014) of the Korean Children & Youth PanelSurvey collected by the South Korean National Youth Policy Institute. We employed a latent growth curve modeling approach to estimate an unobserved latent trajectory and to test the longitudinal effects of child abuse and neglect on BMI. Our results indicate that child abuse is significantly associated with BMI and children who report higher levels of abuse tend to have higher rates of increase in their BMI. This study addresses a gap in the literature by demonstrating that a parent's maltreatment of their child has a long-term effect on the rate of change in their BMI over time.