Both HIV disease and frailty syndrome are risk factors for neurocognitive impairment. Longitudinal research among individuals of the general population suggests that frailty predicts future cognitive decline; however, there is limited evidence for these longitudinal relationships among people living with HIV (PLWH). The current study evaluated and compared rates of cognitive decline over 2 years among HIV serostatus and frailty status groups. Participants included 50 PLWH and 60 HIV-uninfected (HIV−) participants who were evaluated at baseline and 2-year follow-up visits. Baseline frailty status (non-frail, pre-frail, and frail) was determined using fried frailty phenotype criteria. Neurocognitive functioning was measured using practice-effect corrected scaled scores derived from a comprehensive neuropsychological battery covering seven cognitive domains. Repeated measures analysis was used to estimate rates of global and domain-specific cognitive change from baseline to 2-year follow-up among each of six HIV/frailty status groups. Among PLWH, the pre-frail group demonstrated consistent declines in global cognitive functioning (B = − 0.029, p = 0.034), processing speed (B = − 0.047, p = 0.031), and motor functioning (B = − 0.048, p = 0.038). Among HIV− participants, pre-frail individuals also declined in global cognitive functioning and processing speed (ps ≤ 0.05). HIV− non-frail participants also declined in the cognitive domains of learning, delayed recall, and motor functioning; however, these declines appeared to be driven by relatively higher baseline scores among this group. Notably, 38% of PLWH changed in frailty status from baseline to follow-up, and those with stable pre-frailty demonstrated higher likelihood for cognitive decline; change in depressive symptoms did not relate to change in frailty status. Current findings highlight pre-frailty as an important clinical syndrome that may be predictive of cognitive decline among PLWH. Interventions to prevent or reduce frailty among vulnerable PLWH are needed to maintain optimal cognitive health.