Objective: High rates of sexually transmitted infections (STIs) and human immunodeficiency virus (HIV) can be found in states in both the Appalachian and Southeastern regions of the United States. As infection rates increase, it is imperative to understand factors that improve HIV prevention. The current work explored whether HIV conspiracy beliefs influences the link between HIV testing attitudes and perceived prevention ability. Participants: Four samples were collected during Fall 2013 (N = 373), Spring 2014 (N = 231), Fall 2014 (N = 345), and Spring 2015 (N = 369) at a rural, Southeastern, Appalachian university. Methods: Participants in all samples completed an online survey. Results: Four studies showed that HIV conspiracy theory beliefs mediated the relationship between HIV testing attitudes and HIV prevention self-efficacy. Conclusions: HIV conspiracy theory beliefs at least partially explain the connection between testing attitudes and HIV prevention self-efficacy. Results have implications for the role of HIV testing attitudes, beliefs, and self-efficacy.