In this paper I examine the controversy over genetically modified canola (GM canola) in Australia as an ontological politics, drawing on recent work in Science and Technology Studies that extends actor-network theory and its commitment to the contingency of reality. I examine three different and overlapping performances of GM canola: as an agronomic object, a risk object and a market object. I focus on how each performance effects similarities and differences between GM and conventional canola that are productive of ontological distinctions that make GM canola controversial. I argue this analysis offers useful insights that are not revealed by more traditional explanations of controversy.