Cardiovascular disease (CVD) is a leading cause of death in South Africa (SA) and high blood pressure (BP) is the primary risk factor. However, hypertension prevalence is high, BP control is poor and CV events occur at a younger age than in Europe or America. Increasing screening, raising awareness and improving management of hypertension are critical to prevent CVD in SA. May Measurement Month (MMM) is a global initiative of the International Society of Hypertension aimed at raising awareness of high BP. As part of the MMM campaign, in SA (2017, 2018, 2019 and 2021), BP measurements and a cross-sectional survey of volunteers aged ≥ 18years were performed. Of 11,320 individuals (age 36.6 ± 16.8years) screened, 29.7% had hypertension (systolic BP/diastolic BP ≥ 140/90 mmHg or antihypertensive medication use) and the prevalence was higher (p < 0.0001) in men (35.6%) than in women (26.3%). Of those with hypertension, only 54.3% were aware and 46.8% were receiving antihypertensive medication, and 53.7% of these had controlled BP. In men with hypertension, awareness (45.2%, treatment (38.2%) and controlled BP on antihypertensive medication (45.2%) were lower (p < 0.0001) than in women (awareness: 60.8%; treatment: 53.5%; controlled BP: 58.3%). In young participants (age < 40years), 15.6% had hypertension, 18.6% of these were on treatment but 76.0% were not aware, and only 57.7% had controlled BP. The high prevalence of hypertension, but low levels of awareness, treatment, and BP control in SA, especially in young adults and men, highlight the need for systematic BP screening programmes and improvements in education and management of hypertension.