The American survey, which involved 568 women, also found that 27 per cent of the women performed oral sex on the first date.
Felicity Percival, editor of Women's Health magazine, revealed why the results, though worrying were not surprising.
She said that women, in general, are 'holding out more' and the '12 date rule' is becoming popular. However, talking to someone online over a period of time tends to make people comfortable and lulls them into a false sense of security.
"People do feel more comfortable with each other when they've had lots of conversations online, whether it's through RSVP, Facebook, or any online social network," News.com.au quoted her, as saying.
"If you think 'I know that person, I'm sure they're safe', you're less likely to use a condom.
"Just because you talk to someone online does not mean you know them, and doesn't mean they're free of genital warts or herpes.
"You need to raise these issues with that person before you meet them. You should keep sex sacred, at least for the first few times you meet them.
"It's really important to get the safe sex message out there, whether you meet in a bar or online.