And these veterans were 1.5 times as likely as other veterans to need mental health services, the report from the VA found.
"We are, in fact, detecting men and women who seem to have a significant need for mental health services," said Rachel Kimerling of the National Center for Posttraumatic Stress Disorder at the VA Palo Alto Health Care System in California.
The study, presented at a meeting of the American Public Health Association in San Diego, raises many questions.
Kimerling said in a telephone interview the term "military sexual trauma" covers a range of events from coerced sex to outright rape or threatening and unwelcome sexual advances.
Kimerling said for her purposes it is not necessary to find out what kind of sexual trauma occurred. Her study also did not determine when it happened.
"If you think about military service where you are living and working so closely with the same people, that even if it is not sexual assault ... it is possible that severe sexual harassment is just as traumatic," she said.
The study does not cover active-duty servicemen and women, as VA services are only available to discharged veterans.
A spokeswoman for the VA said about 40 percent of all discharged veterans who served in Iraq and Afghanistan have sought medical care of some sort from the VA, which has a universal screening program for military sexual trauma.
Kimerling said that may mean many veterans are unaware they can be helped and she said she hoped more would come forward to seek treatment.