Candidates were tested in two groups about a week apart. About 20 percent of the recruit candidates in each group evidenced drug, primarily marijuana, use. As part of a psychological screening test battery all the candidates took the Inwald Personality Inventory (IPI). The IPI contains a self-report Drug Use Scale. Drug-Positive and Drug-Negative candidates' Drug Use Scale scores were matched by age, sex, and racial/ethnic group and compared to evaluate the accuracy of self-reported drug use when screening police recruit candidates. Results showed that Drug-Positive candidates' self-reported drug use was consistently higher than that of Drug-Negative candidates. Item-level analyses showed which drug use items best discriminate between Drug-Positive and Drug-Negative candidates. Implications are drawn for use of self-report as part of a police candidate screening process. (Author abstract)