Previous research has reported associations between childhood physical abuse and Body Mass Index (BMI) in adulthood. This paper examined the role of four potential mediators (anxiety, depression, posttraumatic stress, and coping) hypothesized to explain this relationship. Using data from a prospective cohort design, court-substantiated cases of childhood physical abuse (N = 78) and non-maltreated comparisons (N = 349) were followed-up and assessed in adulthood at three time points (1989-1995, 2000-2002, and 2003-2005) when participants were ages 29.2, 39.5, and 41.2, respectively. At age 41, average BMI of the current sample was 29.97, falling between overweight and obese categories. Meditation analyses were conducted, controlling for age, sex, race, smoking, and self-reported weight. Childhood physical abuse was positively associated with subsequent generalized anxiety, major depression and posttraumatic stress disorder symptoms at age 29.2 and higher levels of depression and posttraumatic stress predicted higher BMI at age 41.2. In contrast, higher levels of anxiety predicted lower BMI. Coping did not mediate between physical abuse and BMI. Anxiety symptoms mediated the relationship between physical abuse and BMI for women, but not men. These findings illustrate the complexity of studying the consequences of physical abuse, particularly the relationship between psychiatric symptoms and adult health outcomes.