The trauma most commonly associated with the military is combat-related trauma. It is increasingly recognised that childhood sexual and physical abuse and military sexual assault may influence or exacerbate posttraumatic stress disorder (PTSD) when military members are exposed to combat. The study aimed to determine whether a history of childhood sexual and physical abuse would increase the likelihood of military sexual assault (MSA) and determine whether a history of sexual abuse (childhood or military) impacted the incidence and severity of post-trauma sequelae compared to veterans without this history. A retrospective correlational analysis was performed on baseline data collected from clinical case records of a cohort of 134 Australian veterans with PTSD who had attended an outpatient Military Service Trauma Recovery Day Programme between October 2020 and May 2022. Almost half (48.5%) of veterans reported a history of abuse. Prevalence rates of military sexual abuse, child sexual abuse and child physical abuse were 14.9%, 13.4% and 23.1% respectively. The relationship between those who experienced childhood abuse and those who experienced military sexual abuse was not significant. No significant differences were observed between those who experienced any sexual abuse and those who did not on intake scores of psychological symptoms. This is the first Australian study to investigate the prevalence of childhood abuse and military sexual abuse and its impact on PTSD and associated psychopathology in a sample of veterans seeking mental health treatment. No additional risks of experiencing military sexual assault were found for those who had survived childhood sexual abuse.