According to the Indiana University survey of nearly 6,000 people, ranging in age from 14 to 94:
79 percent of boys ages 14 to 17 reported using a condom on the most recent occasion, compared to 25 percent for all the men in the survey.
Rates of condom usage among black and Hispanic men were significantly higher than for whites.
The lowest condom usage rates overall were for men over 50, a finding the researchers described as worrisome.
While about 7 percent of adult women and 8 percent of men identify as gay, lesbian or bisexual, the proportion of individuals who have had same-gender sex at some point in their lives is higher. For example, 15 percent of the men aged 50-59 said they had received oral sex from another man at some point.
Among adolescent boys, only about 2 percent of the 14-year-olds -- but 40 percent of the 17-year-olds -- said they had engaged in sexual intercourse in the past year.
85 percent of men reported that their partners reached a climax during their most recent sexual relations. Only 64 percent of women said they actually achieved orgasm.
Researchers counted 41 different ways in which the subjects engaged in sex, encompassing vaginal and anal intercourse, oral sex, and partnered masturbation.
Dr. Dennis Fortenberry, a pediatrics professor involved in the study, said the overall findings of such a huge survey should provide reassurance to Americans who are curious about how their sex lives compare with others.
"Unless, like al Qaeda, you feel there's something abnormal about the American people, what these data say is, 'This is normal - everything in there is normal."'
The Associated Press contributed to this report.