Most US troops think allowing gays to serve openly in the military would have a minimal effect on US war efforts, the Washington Post newspaper reports.
Some 70% of troops surveyed said the effects of repealing the ban would be positive, mixed or nonexistent, the paper said, citing a Pentagon report.
US President Barack Obama has called for an end to the policy.
But hopes for a repeal dimmed this month amid conservative Republican gains in the US Congress.
According to the newspaper, which spoke to people who had read the unreleased 370-page study, the survey results have led the report's authors to conclude that objections to openly gay colleagues would drop once troops were able to live and serve alongside them.
However, a significant minority opposes serving alongside openly gay troops, with opposition apparently strongest in the Marine Corps.
Troops' young age
Britain, Israel and dozens of other countries allow gay personnel to serve openly, but under the US policy established in 1993, gays may serve in the military but cannot acknowledge their orientation. The military is forbidden to inquire but may expel service members found to be gay.
Richard Socarides, former gay and lesbian policy adviser to President Bill Clinton, told the BBC the report was not surprising considering the relatively young average age of the troops.
"This is not a big deal for them," said Mr Socarides, who said he had discussed the report with people who had seen it. "Young people have gay friends."
Pentagon officials have said allowing openly gay military personnel would necessitate dramatic policy changes on everything from housing and insurance to protocol at social events.
The Pentagon is expected to deliver the report to US Secretary of Defense Robert Gates on 1 December.
Meanwhile, two federal courts have ruled the "don't ask, don't tell" policy unconstitutional, saying it violates gay troops right to free speech by effectively forbidding them from discussing their personal lives.
Though Mr Obama favours repealing the ban, he has said the change should come through legislation, rather than the courts, and has appealed against the rulings.
A Republican-led minority in the US Senate in September blocked debate on a provision to repeal the ban.
In this month's elections, the Republican party took control of the House of Representatives and strengthened its numbers in the Senate, dimming hopes of speedy action on the ban.