ABSTRACT
Perceptions and consequences of co-worker substance use were assessed to (1) examine perceptions of co-worker use as supplemental measures of substance use problems in organizations, and (2) examine relationships with employee perceptions and attitudes. Support for the hypothesis that exposure to co-worker substance use is negatively associated with job performance and attitudes is presented. Results suggest the utility of evaluating perceptions of co-worker substance use in assessments of drug use in the workplace. These results have implications for training and education programs which should emphasize that employee substance use is a problem that extends beyond the substance-using employee.