In a new survey 62 percent of employers indicated they had contacted a job applicant's references and found the reference did not give the candidate a positive review.
In addition, 29 percent of the respondents indicated that they had discovered a phony reference listed on a job candidate's application, CareerBuilder said in a statement.
"You want to make sure you are including your biggest cheerleaders among your job references," said Rosemary Haefner, vice president of Human Resources at CareerBuilder.
"Before choosing someone, ask yourself, 'Did this person understand my full scope of responsibilities? Can he or she vouch for my skills, accomplishments and work ethic?'"
"You also want to make sure that you ask your former colleagues if you can list them as a reference. If someone is unwilling, it helps you to avoid a potentially awkward or damaging interaction with an employer of interest," Haefner said.
Among the potential mistakes for job seekers, 15 percent indicated they had failed to tell some people they were listing them as a reference.
The survey found eight of 10 employers indicated they called references with 16 percent indicating they contacted references before they contacted the job candidate.
In addition, 47 percent of employers indicated a reference had changed their opinion for the worse about a job candidate while contacting a reference and 23 percent indicated a reference had altered their opinion to one that was more favorable toward the job candidate.
The survey was conducted online by Harris Interactive. It involved responses from 2,494 employers and 3,976 workers.
Harris said with a 95 percent probability, the results of the survey were accurate with a margin of error of plus and minus 1.96 percentage points.