As part of a blind longitudinal study, 5,465 job applicants were tested for use of illicit drugs, and the relationships between these drug-test results and absenteeism, turnover, injuries, and accidents on the job were evaluated. After an average 1.3 years of employment, employees who had tested positive for illicit drugs had an absenteeism rate 59.3% higher than employees who had tested negative (6.63% vs. 4.16% of scheduled work hours, respectively). Employees who had tested positive also had a 47% higher rate of involuntary turnover than employees who had tested negative (15.41% vs. 10.51%, respectively). No significant associations were detected between drug-test results and measures of injury and accident occurrence. The practical implications of these results, in terms of economic utility and prediction errors, are discussed.