ABSTRACT Older Latinx adults in the US are at a greater risk of developing Alzheimer's disease (AD) and related dementias (ADRD). They exhibit a faster cognitive decline than non-Hispanic whites. However, they remain vastly underrepresented in research studies to characterize risk factors associated with progressive cognitive decline. A better understanding of risk factors can provide better treatment and design appropriate preventive strategies for older Latinx adults. Since older Latinx adults have a higher prevalence of cardiovascular risk factors, their risk of developing ADRD is high in old age. Older Latinx communities were disproportionately affected by the COVID-19 pandemic, which can increase their risk for neurological disorders. This UH2/UH3 cooperative agreement aims to engage and develop the infrastructure for a new Latinx cohort study with the following aims: (1) build infrastructure, community outreach, and the external advisory board for a new Latinx cohort; (2) develop ongoing engagement with the community and resource sharing plan; (3) collect data on 250 Latinx participants from East Side sampling frame; and (4) test the exploratory hypotheses that Latinx participants have a higher prevalence of clinically diagnosed AD and MCI, and the impact of COVID-19 on AD is more severe compared to non-Hispanic whites, and the ApoE4 association with clinical AD and MCI is the same as NHW. The long-term objective is to perform a sizeable muti-ethnic study, combining the Latinx cohort with our existing Chicago Health and Aging Project (CHAP), a population-based community study in four neighborhoods with 10,801 participants with 63% non-Hispanic Black and 37% non-Hispanic white participants. This UH2/UH3 proposal will add a new Latinx cohort in the East Side community of Chicago, with over 60% Latinx. A multi-ethnic cohort will allow us to test several biological and psychosocial hypotheses of high public health significance. The collection of biospecimens will also allow for testing further blood biomarker hypotheses, developing an omics pipeline down the road, and providing additional infrastructure for pathology studies in a population-based cohort study with minorities.