Although South Africa has an adequate food supply nationally, household level food insecurity is still prevalent. One well-known social security intervention, the South African social grant programme, aims to provide financial relief to food-insecure households. However, there is lack of empirical evidence on how deep and broad the food security impact of this programme has been. Employing data from a nationally representative sample and using the instrumental variable method, the study examines this issue by measuring the resilience these households have towards vulnerability to food insecurity. The findings revealed that households receiving social grants are vulnerable to food insecurity. Chronic food insecurity prevails in rural-dominated provinces, while urban-dominated provinces mostly have transient food insecurity. Although this programme targets the poor, its unintended negative impact on economic activities would require policy priority. People with disabilities, female-dominated rural households, and environmentally friendly economic activities should all be prioritised in policy.