BackgroundDiabetes is a complex health condition requiring medical therapy and lifestyle modifications to attain treatment targets. Previous studies have not fully explored factors associated with adherence to medication, diets and physical activity recommendations among individuals living with diabetes in rural South Africa. We examined the association between knowledge, health belief and adherence to medication, dietary, and physical activity recommendations and explored self‐reported reasons for non‐adherence.MethodsThis cross‐sectional study was conducted among 399 individuals living with diabetes recruited over 12 weeks from six randomly selected primary healthcare centres in rural South Africa. Sociodemographic and clinical data were obtained by self‐report. Health beliefs, knowledge, and adherence were assessed using validated measures. Descriptive and inferential statistics were carried out.ResultsThe majority (81.7%) of the participants were females, with a mean age of 62 ± 11 years. Only 39% reported adhering to their prescribed medication regimen, 25% reported adhering to dietary recommendations, and 32% reported adhering to physical activity recommendations. The most cited reasons for non‐adherence were lack of access to (n = 64) and cost of drugs (n = 50), perceived high costs of healthy diets (n = 243), and lack of time (n = 181) for physical activity. Level of education was an independent predictor of medication adherence [odds ratio, OR = 2.02 (95% confidence interval, CI: 1.20–3.40)] while diabetes knowledge was independently associated with both medications [OR = 3.04 (95% CI: 1.78–45.12)]; and physical activity adherence [OR = 2.92 (95% CI: 1.04–2.96). Positive health belief was independently associated with adherence to medications [OR = 1.72 (95% CI: 1.15–2.57) and dietary recommendations [OR = 1.75 (95% CI: 1.04–2.96)].ConclusionAdherence to three important self‐care practices, medication, diet, and physical activity, was suboptimal in this study setting. Socioeconomic reasons and access barriers were significant drivers of non‐adherence, while increased knowledge and positive health beliefs were potential facilitators. Efforts to improve medication adherence and foster engagement in healthy lifestyle behaviours must consider patients’ knowledge and health beliefs. Primary healthcare providers should create awareness on the importance of adherence on health outcomes for people with diabetes. Likewise, efforts to increase the availability and affordability of medications for socioeconomically disadvantaged populations should be prioritised by the key health stakeholders.