Despite increasing recognition of the link between health and economic development in low-income countries, the relationship has to date received scant attention in rich countries. We argue that this lack of attention is not justifiable. While the economic argument for investing in health in rich countries may differ in detail from that in low-income countries, there is considerable and convincing evidence that significant economic benefits can be achieved by improving health not only in poor, but also in rich countries. Better health increases labour supply and productivity and historically, health has been a major contributor to economic growth. In spite of remaining evidence gaps economic policy-makers also in developed countries should consider investing in health as one (of few) ways by which to achieve their economic objectives.