Abstract Body: Arsenic exposure is common throughout the world and is associated with cardiovascular disease (CVD). Blood pressure (BP) and arterial stiffening are sensitive measures of subclinical CVD that are common in the Afro-Caribbean Tobagonian population. However, little is known about arsenic exposure and its relationship to CVD in Tobago. We examined cross-sectional associations of urinary arsenic species and total urinary arsenic (TUA) with BP, hypertension, and arterial stiffness in Tobagonian adults. Concentrations of urinary dimethylarsinic acid (DMA), monomethylarsonic acid (MMA), and inorganic arsenic (iAs) were quantified by inductively coupled plasma mass spectrometry in spot urine samples collected from a random subset of 965 participants from the Tobago Health Study. Arsenic concentrations below the limit of detection were imputed as LOD/√2. Total urinary arsenic (TUA) was calculated as the sum of DMA, MMA, and iAs and log-transformed; %DMA, %MMA, and %iAs were calculated as the proportion of DMA, MMA, and iAs in TUA. Participants underwent brachial-ankle pulse wave velocity (PWV) measurement and measurements of BP, height, and weight. Hypertension was defined as systolic BP≥130 mmHg, diastolic BP≥80 mmHg or use of anti-hypertensive medication. Multiple linear and logistic regressions were adjusted for log-transformed urinary creatinine (all models), age and sex (models 2 and 3), height and weight (model 3) and hypertension status (model 3 for PWV outcomes). Predictors were calculated for 805 individuals without missing data. The median age of this sample was 58 years (range 40-84); 48.2% were female and 72.9% had hypertension. Raw mean ± SD TUA was 16.6±17.6 ng/mL and mean (range) for proportions were: DMA: 80% (22-99%), MMA: 12% (0.2-41%), iAs: 6% (0.6-50%). In model 1, TUA, %DMA and %iAs were associated with higher SBP and greater odds of hypertension and %MMA was associated with lower SBP and lower odds of hypertension; associations were attenuated after adjusting for age and sex (Table). All predictors were associated with PWV in model 1; the association between greater %MMA and lesser PWV was independent of age, sex, height, weight and hypertension (Table). In a sample of Tobagonian adults, TUA was associated with increased BP and PWV. Further research is needed to fully understand the relationships between arsenic exposure and metabolism and CVD in Afro-Caribbean populations who are at high risk for both arsenic exposure and CVD.