As more local, state, and national governments change laws regarding the legality of cannabis use, it is essential for organizations to understand how the workplace may be influenced by these changes. The current study begins to answer this question by examining the relationship between three temporal-based cannabis measures and five forms of workplace performance. Using data from 281 employees and their direct supervisors, our results indicate that cannabis use before and during work negatively relate to task performance, organization-aimed citizenship behaviors, and two forms of counterproductive work behaviors. At the same time, after-work cannabis use was not related (positively or negatively) to any form of performance as rated by the user’s direct supervisor. We discuss methodological, theoretical, and practical implications for researchers, organizations, and governmental agencies concerned with cannabis use.