This chapter examines Kuhn’s views on reference-fixing, with specific focus on his relation to the casual theory of reference. The causal theory was conceived part in response to the incommensurability arguments of Kuhn and Feyerabend, and proponents argued that it could secure continuity between scientific theories. Kuhn in turn argued that the casual theory worked for objects, but not for kind terms. The reception of Kuhn’s criticisms has been mixed, with some arguing that his arguments hold water, while others make the case that his objections were largely irrelevant. We begin by examining reference in Structure and the development of the causal theory, before examining Kuhn’s arguments and the responses to them.