While Eastwood said his presentation was "very unorthodox," that was his intent from the outset and he had plenty of people giving him advice on what to say.
"Everybody had advice for me, except the janitor," Eastwood said.
Eastwood said he was told to speak for five minutes but he said it was difficult to gauge time and there weren't any signals or cues telling him to wrap up.
Romney and his running mate, Paul Ryan, later came backstage to thank him.
"They were very enthusiastic, and we were all laughing," Eastwood said.
Eastwood, who stars in the upcoming movie "Trouble with the Curve," maintains Obama doesn't deserve a second term as president.
"President Obama is the greatest hoax ever perpetrated on the American people," Eastwood said. "Romney and Ryan would do a much better job running the country, and that's what everybody needs to know. I may have irritated a lot of the lefties, but I was aiming for people in the middle."