The way in which agricultural biotechnology is regulated and the property rights that are granted over the technology have important consequences and can impact – negatively or positively – on food security, the health of the agricultural sector, and the well-being and development of affected communities. The task of regulating the technology is not a simple one. It requires careful calibration, using a complex web of laws, to balance competing public and private interests. In this article, the use of patent-protected genetically engineered cotton seed by South African farmers, with a particular focus on small-scale farmers in Makhathini, KwaZulu Natal, is analysed through a sustainable development lens. Concerns are raised about the developmental impact of the proprietary technology, theoretical aspects of the property concept are discussed and possible areas for reform are outlined.