INTRODUCTION: Living with HIV has been proposed as a risk factor for the early development of functional decline. Composite marker tools like the Veterans Aging Cohort Study (VACS) Index, which includes HIV-associated and non-HIV-related markers of disease may better reflect multi-organ system injury and potentially predict functional outcomes. Therefore, the objective of this work is to determine whether higher VACS 2.0 Index scores predicts functional decline among older adults living with HIV (OALWH). MATERIAL AND METHODS: Longitudinal study including 131 adults aged 50 or older who underwent a comprehensive geriatric assessment at baseline and follow-up, at least a year apart. Functional status was determined by the gait speed (seconds for a 4-meter distance). Linear regression models were constructed to determine the relationship between VACS 2.0 index at baseline with gait speed at follow-up adjusted for potential confounders. RESULTS: The median for age was 58.0 years (range 50 - 84), and 81.7% were male. At baseline, the median VACS 2.0 index score was 50.4 (IQR 42.2-65.3). The adjusted linear regression analysis found that higher baseline VACS 2.0 Index scores were significantly associated with a decline in gait speed (p = .033) at follow-up. DISCUSSION: The results suggest that the VACS 2.0 Index works as a predictor of functional decline as showed by decline in gait speed and might serve as an easy tool to identify OALWH who might need additional resources or interventions to prevent it.Read less <