Abstract <p>Subjective cognitive decline (SCD) is a self-perceived deterioration in cognitive function and has been linked to both cognitive and physical decline. This study aimed to examine whether persistent SCD is associated with frailty after 3 years. A longitudinal cohort study using mailed questionnaires was conducted among community-dwelling older adults in Japan. Questionnaires were distributed at baseline, 6 months, and 3 years, assessing subjective cognitive complaints and frailty using validated screening tool. Sociodemographic and health related data were also collected. Participants who responded at all three time points and remained traceable throughout the study were included. Participants were divided into persistent SCD (consistently complaining of SCD for six months) and non-persistent SCD (had no complaint or complained intermittently) groups. Multiple regression analysis was employed to examine the association between frailty three years later and persistent SCD. In total, 268 participants were included in the analysis: 38 (14.2%) and 230 (85.8%) in the persistent and non-persistent (180 (67.2%) had no complaint and 50 (18.6%) complained intermittently) SCD groups, respectively. Multiple logistic regression analysis showed that persistent SCD was associated with frailty after 3 years, even after adjusting for age, sex, comorbidity, cohabitants, and frailty status at baseline (OR = 3.13, 95% CI: 1.25–7.79). Persistence of SCD over 6 months was significantly associated with frailty after 3 years. Our findings suggest that persistent SCD may contribute to frailty progression through psychological factors, particularly depression or anxiety, thereby highlighting the importance of early intervention and targeted support for individuals with SCD.</p>