Objectives: Adverse childhood experiences (ACEs) have been consistently linked in a strong and graded fashion to a host of health problems in later adulthood but few studies have examined the more proximate effect of ACEs on health and emotional well-being in adolescence. Study design: Nationally representative cross-sectional study. Methods: Using logistic regression on the 2011/12 National Survey of Children's Health, we examined the cumulative effect of total ACE score on the health and emotional well-being of US adolescents aged 12 to 17 years. We investigated the moderating effect of family functioning on the impact of ACE on adolescent health and emotional well-being. Results: Adolescents with higher ACE scores had worse reported physical and emotional well-being than adolescents with fewer ACEs net of key demographic and socio-economic characteristics. Family functioning moderated the negative impact of cumulative ACE on adolescent health and emotional well-being. Conclusions: Adolescent well-being has enduring consequences; identifying children with ACE exposure who also have lower-functioning family could also help identify those families at particular risk. (C) 2015 The Royal Society for Public Health. Published by Elsevier Ltd. All rights reserved.