Exposure to radon continues to be a leading cause of lung cancer despite the availability of effective testing and mitigation options. This study examined differences in beliefs about radon testing among radon testers (n = 110) and a comparison sample of residents (n = 198) in Utah County, Utah, which is a high radon area. Structural equation modeling was used to analyze relationships between radon testing status and self-efficacy, knowledge, behavioral modeling, and risk perception. Risk perception (0.20, p < .04), self-efficacy (0.30, p < .01), and knowledge (0.40, p < .001) were positively associated with testing. Behavioral modeling was indirectly associated with testing through intervening pathways of self-efficacy (z = 1.97, p < .05) and knowledge (z = 2.57, p = .01). The results imply that increasing radon knowledge and self-efficacy, along with traditional intervention efforts focusing on risk perception, might be important factors to increase radon testing in residential areas.