South Africa's public agricultural extension services evolved from as early as the beginning of 1900. Agricultural extension is now recognised as a science by the South African Council of Natural Science Profession (SACNASP). This paper presents a philosophical argument that the promotion of sustainable agricultural practices should remain the domain of public extension and advisory services. To provide context, the paper firstly defines agricultural extension and the role extension could play in promoting the five pillars of sustainable agriculture. Secondly, it evaluates the national policy on extension and advisory services to determine the extent to which it addresses the framework of the five pillars for sustainable agriculture. Thirdly, the paper evaluates the Extension Recovery Plan (ERP), norms and standards for agricultural extension and the National Development Plan (NDP) against the framework of sustainable agriculture. The evaluation indicates that only three pillars of sustainability are emphasised. There is a need to subdivide the traditional pillars to align with the full framework for sustainability. The initial findings suggest that, while South Africa's agricultural extension policy often refers to sustainability and even to sustainable agriculture, they do so using the traditional three-pillared framework of economic, environmental and social sustainability, and thus fall short on key elements essential to sustainable agriculture, namely maintaining and increasing biological productivity, decreasing the level of risk to ensure larger security, protecting the quality of natural resources, ensuring agricultural production is economically viable, and ensuring agricultural production is socially acceptable. The paper also explores government initiatives to support extension and advisory services. Finally, this paper concludes by emphasising that the national policy on extension and advisory services should be amended to suit the five pillars of sustainable agriculture.