Causal Set Theory (CST) is a promising approach to fundamental physics that seems to treat causation as a basic posit. But in exactly what sense is CST causal? We argue that if the growth dynamics is interpreted as a physical process, then CST employs relations of actual causation between causal set elements, whereby elements bring one another into existence. This is important, as it provides a better sense of how CST works, highlights important differences from general relativity—where relations between spacetime points are typically seen as cases of mere causal connectibility rather than actual causation of the relevant type—and points toward a specific understanding of the emergence of spacetime within CST.