We studied the community prevalence, patterns and predictors of hypertension in a large sub-population of South Asian adults with a view of identifying differential risk factors. Data were collected between years 2005–2006 and 5000 adults were invited for the study. The sample size was 4485, and about 39.5% were males. Mean systolic and diastolic blood pressures were 127.1?±?19.8?mmHg and 75.4?±?11.3?mmHg, respectively. Age-adjusted prevalence in all adults, males and females was 23.7%, 23.4% and 23.8%, respectively. Urban adults had a significantly higher prevalence of hypertension than rural adults. In the binary logistic–regression analysis, male gender (OR: 1.2), increasing age, Sri Lankan Moor ethnicity (OR: 1.6), physical inactivity (OR: 1.7), presence of diabetes (OR: 2.2) and central obesity (OR: 2.3) all were significantly associated with hypertension. In conclusion, nearly one-third of the Sri Lankan adult population is hypertensive. Hence, public health initiatives should encourage healthier lifestyles with emphasis on preventing obesity and increasing physical activity.