To date, little is known about the risk of developing mental health problems in adults who were exposed to intimate partner violence (IPV) during childhood. Based on a representative and randomly selected sample of 2,500 Swedish young adults, this study used retrospective self-report to (1) determine the prevalence of childhood exposure to IPV among young adults in Sweden and (2) examine the relationships between childhood exposure to IPV and child gender, age of exposure and adult mental health problems. Twenty eight percent of all participants reported witnessing IPV during childhood. Women were younger at first exposure and exposed to more severe violence than men. Severity of the IPV was related to all mental health symptoms measured. Exposure to IPV was significantly related to adult depression, anxiety, posttraumatic stress, and ADHD symptoms for women but only to ADHD symptoms for men. Implications of these results for practice and policy are discussed.