Three axioms underpin consumer choice in neoclassical theory: weak order, independence, and continuity. Two of these axioms may not hold, however, for consumers’ choices regarding genetically modified (GM) food. Consumers may evaluate product attributes differently depending on whether the food is GM or not, violating attribute independence. Some consumers may not want GM food at all, violating continuity. The axioms were empirically investigated with a choice experiment survey. The paper discusses evidence of violations of both independence and continuity, as well as a non-neoclassical approach to modelling consumer choice.