Fifty-five percent of 1,648 respondents to a random survey said they had been "protected from harm by a guardian angel," representatives of the Baylor University Institute for Studies of Religion said at a Washington news conference.
"That was something that was a complete surprise because this is not a question, do you believe in guardian angels or do you believe in angels," survey director Christopher Bader said.
"This is a very specific question: Do you believe you have been protected from harm by a guardian angel? Do you believe you avoided an accident through the agency of a guardian angel? To find out that more than half of the American public believes this was shocking to me. I did not expect that," Bader said.
Evangelical and black Protestants are more likely than mainline Protestants, Catholics or Jews to report religious or mystical experiences, the survey found.
Women, African-Americans and Republicans are also more apt to have mystical experiences than the average, the survey found.
Even 20 percent of those saying they have no religion said they experienced angelic intervention, the survey found.
The phone and mail survey, conducted for the institute by the Gallup Organization in October and November 2007, has a margin of error of 4 percentage points.