Limited research has investigated exercise imagery use in middle-aged and older adults and its relationship with affective and behavioral correlates. The study examined the association between self-regulatory imagery and physical activity (PA) through key social cognitive variables. Middle-aged and older adults (N = 299; M age = 59.73 years, SD = 7.73, range = 50 to 80) completed self-report measures assessing self-regulatory imagery use, self-efficacy, outcome expectations, perceived barriers, self-regulatory behavior, enjoyment, and PA levels. Path analysis supported a model (χ² [14] = 21.76, p = .08, CFI = .99, TLI = .97, SRMR = .03, RMSEA = .04) whereby self-regulatory imagery positively predicted self-efficacy, outcome expectations, and self-regulatory behaviors. Furthermore, self-regulatory imagery indirectly predicted barriers, outcome expectations, self-regulation, enjoyment, and PA. This research highlights self-regulatory imagery as an effective strategy in modifying exercise-related cognitions and behaviors. Incorporating social cognitive constructs into the design of imagery interventions may increase PA engagement.