Background A long line of research has examined whether being the victim of sexual assault is associated with negative and maladaptive outcomes, but has mainly focused on women and girls. Aims To replicate and extend prior research by examining whether various measures of sexual assault are related to physical ill‐health, depression and/or suicidal ideation, regardless of sex or age of victim. Our research questions were (1) is sexual assault related to health problems, depression and suicidal ideation and (2) do these associations differ between men and women? Method We analyse data from the National Longitudinal Study of Adolescent to Adult Health (Add Health), a longitudinal study of a US nationally representative sample of nearly 21,000 young people recruited for the first wave of interviews when most of the participants were between ages 12 and 18 years. We used Wave 4 data, collected for participants who were in their 20s and 30s, on experience of both physical sexual assault and non‐physical sexual assault and mental state, allowing for some characteristics measured in Wave 1. Allowing for missing data, sample sizes were between 6868 and 10,489 for the women and 6024 and 10,263 for the men. Results Statistically significant associations were revealed between the physical and non‐physical measures of sexual assault and the health problems scale, the depression scale and the measure of suicidal ideation. These associations remained statistically significant even after controlling for key covariates measured at Wave 1, including exposure to delinquent peers, poverty and demographic characteristics. Conclusions Sexual assault at some time and of whatever kind, although more commonly reported by women than men, is similarly associated with serious physical and mental health problems during their 20s and 30s. More sequencing detail is required for better prevention of harms.