The purpose of this study was two-fold. First, the proposed study aimed to create a reliable survey instrument designed to examine the nonmedical use of prescription stimulants (NMUPS) and diversion behaviors using the Theory of Planned Behavior (TPB) among undergraduate students aged 18-24. Second, this study examined the utility of the TPB in predicting NMUPS and diversion behaviors. The study utilized a cross-sectional design (n=1,026) to administer an 88-question survey assessing the nonmedical use and diversion of prescription stimulants. As part of this survey, students responded to theory-based questions for both behaviors. Results of a principal components analysis suggested strong reliability in the survey's ability to measure the theoretical constructs of diversion and NMUPS. Further statistical analyses found utility for TPB in predicting NMUPS. However, TPB had limited ability in predicting the diversion behavior.