The introduction of genetically modified (GM) food products to food markets around the world, has led to considerable controversy. In many cases consumer attitudes and perceptions of GM food products were revealed as fears, concern for, and avoidance of the new technology. The importance of GM foods in South Africa is increasing, even though the GM Food debate lags behind many other (often more developed) parts of the world. This paper investigates the knowledge, attitudes and acceptance of urban South African white-grain maize consumers regarding GM maize. Conjoint- and cluster analysis were used to develop clusters/market segments among the urban consumers of white maize. A range of additional questions was used to develop profiles of the identified market segments. These aspects covered demographics, GM knowledge aspects as well as GM attitude aspects. Four distinct clusters/market segments were identified with specific characteristics: "Anti-GM, Brand aware" cluster (35% of valid responses), "Brand unaware, Farmer sympathetic" cluster (20%), "GM consumer benefit, Brand aware" cluster (25%) and the "Brand aware, Pro-GM" cluster (20%). The most significant differences between the clusters were based on the consumers' attitudes towards GM food products.