For three decades, Canadian and international researchers have been suggesting that improving population and public health requires attention to a range of determinants and factors and that concerted and coordinated action on the part of non-health ministries and organizations might be necessary to achieve this goal. Suggestions have been made for collaboration and integration by explicitly designing intersectoral actions and interventions and assessing the impact of all policies and programs for their effects on health. While some progress has been made on these goals, it is minor compared to the size of the problem. This article addresses one type of intersectoral action, Health in All Policies (HiAP), and asks questions about why it has not gained a place in governments across Canada. Possible barriers are suggested, such as current structural and political factors that prevent long-range, shared strategies to improve health. Suggestions are made for generating economic and evaluative data on HiAP, developing more sensitive tools for measuring HiAP and adopting explicit “trans-sectoral” approaches to policy-making.