Background: Achieving the blood pressure treatment target in individuals with hypertension is a serious global health challenge. Furthermore, the actual burden of uncontrolled hypertension is poorly understood especially in the developing countries. Therefore, this study comprehensively examined the rate and factors associated with uncontrolled hypertension in individuals receiving care at the primary healthcare facilities in the rural areas of Mkhondo Municipality in the Mpumalanga Province, South Africa.Methods: In this cross-sectional study, individuals attending care for hypertension were recruited from January 2019 to June 2019 at three primary healthcare centres, namely, Piet Retief hospital, Mkhondo town clinic and Thandukukhanya community health centre. Uncontrolled hypertension was defined as systolic blood pressure ≥ 140mmHg and diastolic blood pressure ≥ 90mmHg in accordance with the South African Hypertension Society guideline (2014). Multivariate logistic regression (Forward LR method) analysis was used to identify the significant determinants of uncontrolled hypertension.Results: The majority of the participants were; 55 years old and above (69.0%), Zulus (81.2%), non-smokers (84.19%) and had been diagnosed with hypertension for more than a year prior to the study (72.64%). The overall prevalence of uncontrolled hypertension was 56.83% (n=187) with no significant difference between sexes, 57.38% males versus 56.88% females, respectively. In the multivariate logistic regression model analysis after adjusting for confounding variables, obesity (AOR=2.90; 95% CI 1.66-5.05), physical activity (AOR=4.79; 95% CI 2.15-10.65) and HDL-C (AOR=5.66; 95% CI 3.33-9.60) were the significant and independent determinants of uncontrolled hypertension in the cohort.ConclusionThe high rate of uncontrolled hypertension in the study setting, can be largely attributed to obesity, physical activity and dyslipidaemia. Treatment will require the collaborative efforts of individuals, clinicians and health authorities. All these determinants should be addressed decisively so as to achieve the treatment blood pressure targets in the study population.