Objective: Subjective cognitive decline (SCD) is an important area of research within older populations, for whom prospective memory (PM) functions as a crucial part of daily life. Little is known about change in PM, following reports of SCD. This study examines longitudinal naturalistic PM in older adults with high and low levels of SCD. Method: Ninety-nine community-dwelling older adults were revisited after 5 to 6 years, to examine the role of baseline SCD (measured as reported memory decline from young adulthood) on episodic and habitual PM change. Episodic PM was measured by the message task and habitual PM by a time-stamped button-pressing task across 2 weeks. Results: SCD status was not associated with episodic PM, with performance declining over time across both groups, η2 =.03, 95% CI [.11,.61]. Conversely, for habitual PM, there was a significant Group × Time interaction, η2 =.07, 95% CI [−.95, −.06], with people reporting high SCD demonstrating better baseline performance and declining over time, whereas low SCD remained stable. Conclusions: Older adults with SCD demonstrated greater decline in habitual PM, suggesting these tasks may be more sensitive to the effects of SCD. (PsycInfo Database Record (c) 2021 APA, all rights reserved) Key Points—Question: Are older adults’ subjective reports of worsening memory and thinking associated with objective decline in prospective memory over 5 years? Findings: Older adults who report high levels of subjective cognitive decline experience decline in prospective memory within the context of everyday memory and routines, rather than single-event tasks. Importance: The findings suggest that subjective cognitive decline subtly influences the everyday functioning of older adults and may have implications on everyday tasks that require prospective memory such as medication adherence and other essential habitual tasks required for independent living. Next Steps: Future research should continue to utilize habitual prospective memory tasks within naturalistic settings to detect significant change over time across a number of samples of older adults who are experiencing subjective and objective memory decline. (PsycInfo Database Record (c) 2021 APA, all rights reserved)