Of those who have become romantically involved with someone at work, 98 percent said it did nothing to advance their careers, the online job service's annual survey said.
About four-in-10 workers have given romance with a co-worker a try and 20 percent of the 6,700 workers who took part in the survey have tried it twice.
"Dating a co-worker appears to be more accepted in the office these days with 66 percent of workers saying they do not have to keep their romances a secret at work," Rosemary Haefner of CareerBuilders said.
Thirty-seven percent of the women polled said they dated someone who outranked them at work, while 20 percent of men said they had tried dating someone higher on the company totem pole.
Even if it didn't boost their careers, a third of those polled said dating advanced to a marriage. However, six percent left a job because of the repercussions of a job-related romance.