The Log Cabin Republicans endorsed McCain, R-Ariz., Tuesday at the Republican National Convention in St. Paul, Minn., CNN reported.
"He's a very inclusive Republican, a different type of Republican," said the group's president Patrick Sammon. "At the same time, we have honest disagreements on some issues."
While McCain opposes same-sex marriage, he also opposed a federal constitutional amendment that would have defined marriage as being between a man and a woman.
While McCain's running mate, Gov. Sarah Palin of Alaska, has expressed support for the federal amendment, she vetoed a bill that would have banned her state from giving benefits to same-sex partners of employees.
"She's a great choice," said Log Cabin member David Valkema of Illinois. "We're learning more every day but what we know, we like."
Exploding whale video goes viral on Internet
Wisconsin business offering 'therapeutic cuddling' forced to close