Despite its scientific and practical importance, relatively few studies have been conducted to investigate the relationship between job applicant mental abilities and faking. Some studies suggest that more intelligent people fake less because they do not have to. Other studies suggest that more intelligent people fake more because they have increased capacity to fake. Based on a model of faking likelihood, we predicted that job candidates with a high level of mental abilities would be less likely to fake a biodata measure. However, for candidates who did exhibit faking on the biodata measure, we expected there would be a strong positive relationship between mental abilities and faking, because mental abilities increase their capacity to fake. We found considerable support for hypotheses on a large sample of job candidates (N=17,368), using the bogus item technique to detect faking.