This paper presents a critical analysis of health impact assessment (HIA) in the Republic of Ireland (ROI) in the context of institutional policy and practice. It begins with a brief background to the origins and aims of HIA. Core developments in health and environmental sectors pertaining to HIA in the ROI are then considered. A series of significant developments have taken place in these sectors over the past decade that are positively associated with the promotion of HIA in the ROI. However, it is argued that in spite of various institutional facilitators, the practice of implementing HIAs in the ROI is significantly underdeveloped, and it continues to lag behind several of its European Union counterparts. It is contended that a paradigm change is required in order to address the current policy-action gap. An organisation theory framework is used to assess the implementation problem and a number of suggestions are highlighted as potential facilitators of this process.