Background: Cardiovascular disease is the leading cause of mortality among Haitian adults, having surpassed HIV in the last decade. The natural history of CVD in Haitians including the age of onset, incidence, and role of major risk factors and social determinants is urgently needed to develop prevention and treatment interventions. Objective: This study fills this gap by establishing the first population-representative longitudinal cohort of adults in metropolitan Port-au-Prince to estimate the prevalence and incidence of cardiovascular risk factors, diseases, and associated poverty-related determinants. Methods: The cohort will include 3,000 adults ≥ 18 years, followed for 2-3.5 years, using multistage random sampling from census blocks. Randomly-generated GPS locations were selected in proportion to the estimated population of each block. Community health workers identify one household systematically at each location, collect household information and measure blood pressure during a single visit. Two adults who live in each household are randomly selected to participate in the longitudinal study. Data is collected at baseline and every six months on risk factors (hypertension, diabetes, obesity, dyslipidemia, kidney disease, poor diet, smoking, physical inactivity, and inflammation) and diseases (myocardial infarction, heart failure, stroke and CVD mortality) using AHA definitions. We also measure stress, social isolation, depression, food insecurity and blood lead exposure. Blood, urine, and stool samples are biobanked at enrollment. We report the first 7 months of prevalence data. Results: A total of 585 households (response rate 97%) were surveyed with 566 participants enrolled (51% response rate). The majority of participants are women (73%) with median age 38.5 years with 30% 18-30 years. Over 90% live in extreme poverty (<$2/day) and 26% are unemployed. Prevalence rates of risk factors include 31.5% HTN (15.6% Stage I, 11.11% Stage II, 4.79% history of HTN), 4.4% active smokers, 20.7% obesity (BMI > 30 kg/m 2 ), and 5.1% diabetes. Heart failure was the most common CVD (9.8%), followed by angina/MI (5.6%), and stroke (3.3%). Impact: This study will provide invaluable insights into the epidemiology of CVD in Haiti. The study also builds a platform for comparison research with existing US CVD cohorts. Our goal is to translate findings from this study into pragmatic prevention and treatment interventions to fight the CVD epidemic in Haiti and in Haitian immigrants in the US.