The recent use of Chemical Weapons (CWs) in armed conflicts and terror attacks highlights the importance of understanding their full impact in order to inform an effective response. This article argues that while the consequences of CWs on individual health have dominated our understanding of the impact of these weapons, far less attention has been directed to their impact on public health. A review of the literature on the health impact of CWs was conducted, and two case studies of their use in urban settings were explored - Halabja in northern Iraq in 1988 and throughout Syria’s ongoing conflict. The importance of considering the long-term health consequences of CW use and their impact on healthcare and health systems was demonstrated. This article highlights the importance of supporting future research on the topic and proposes a framework for assessing the public health impact of CW use.