Objective: To investigate whether individual differences in coping self-efficacy mediated the association of child abuse and symptoms of ADHD in young adults. Method: Self-reported measures of coping self-efficacy, child abuse, and ADHD were obtained from 66 adults. Results: Adults who reported childhood physical or sexual abuse (prior to the age of 17) had significantly higher levels of ADHD than those who did not. Individual differences in coping self-efficacy fully mediated the association between child abuse and ADHD symptoms in adulthood, such that individuals who endorsed child abuse had lower coping self-efficacy, and coping self-efficacy negatively predicted ADHD symptoms. Discussion: The findings suggest a potential causal mechanism by which childhood physical and sexual abuse may result in ADHD symptoms later in life. Interventions that improve coping skills may be useful in preventing later ADHD symptoms among adults with a childhood history of physical and sexual abuse.