This paper presents the application of nonparametric quantile regression approach to quantile regression in order to investigate the
associated risk factors of hypertension among adults in South Africa. To estimate the partially linear quantile models, the pivotal method of
inference based on the orthogonal polynomial basis with five knots at the (0.1, 0.25, 0.5, 0.75, 0.95) quantiles were considered. The factors
found to be associated with both Systolic Blood Pressure (SBP) and Diastolic Blood Pressure (DBP) across all quantiles were age, Body
Mass Index (BMI) and gender. Race, highest education, smoking, alcohol consumption and health status were significantly associated with
both SBP and DBP for part of the quantiles. Suggesting that these are risk factors associated with a higher likelihood of developing essential
hypertension in South Africa.