Objective: The goal of this study was to (a) investigate the association between nonprescription stimulant use (NPSU) and risky behaviors, including risky sex, driving, financial behaviors, and drug use and (b) collect preliminary evidence on mechanisms that may link NPSU to risky behaviors. Participants: A sample of 555 college students was collected between August 2010 and February 2012. Methods: Students completed several self-report measures assessing their drug use history, attention-deficit and hyperactivity symptoms, temperament, and risky behaviors beyond drug use. Results: Those who reported more frequent NPSU were more likely to engage in high-risk behavior across all 4 domains studied. Further, effortful control abilities partially mediated the link between NPSU and risky behaviors. Conclusions: These results highlight the associated risks of frequent NPSU for college students as well as provide future directions for examining effortful control as a potentially important mechanism linking NPSU to other risky behaviors.