This study assesses adults' perceptions of and predictors of intention to use prescription drug take-back boxes. This mixed methods study utilized focus groups and an online survey to examine factors related to intention to use a prescription drug take-back box. This study was conducted in [State] during the spring and summer of 2018. Themes identified in focus group data included the importance of take-back box location, benefits of take-back box use (such as reducing opportunities for medication misuse), and barriers to take-back box use (such as lack of awareness, stigma associated with law enforcement). Survey results indicate that pharmacies are the most preferred take-back box location and that attitudes, subjective norms, and perceived behavioral control are statistically significant predictors of intention to use a take-back box. Results suggest that individuals are open to using take-back boxes in secure, convenient locations, but many are unaware of take-back boxes as an option for safe disposal. These findings have implications for health communication and policy efforts designed to increase the use of take-back boxes for prescription drug disposal.