This paper examines patent protection in an endogenous-growth model. Our aim is twofold. First, we show how the patent policies discussed by the recent patent-design literature can influence R&D in the endogenous-growth framework, where the role of patents has been largely ignored. Second, we explore how the general-equilibrium framework contributes to the results of the patent-design literature. In a general-equilibrium model, both incentives to innovate and monopoly distortions depend on the proportion of industries that conduct R&D. Furthermore, patents affect the allocation of R&D resources across industries, and patents can distort resources away from industries where they are most productive.