The operational and policy complexity of civil-military relations (CMR) during public health emergencies, especially those involving militaries from outside the state concerned, is addressed in several guiding international documents. Generally, these documents reflect humanitarian perspectives and doctrine at the time of their drafting, and primarily address foreign military involvement in natural and humanitarian disasters. However, in the past decade, there have been significant changes in the geopolitical environment and global health landscapes. Foreign militaries have been increasingly deployed to public health emergencies with responses grounded in public health (rather than humanitarian) approaches, while public health issues are of increasing importance in other deployments. This paper reviews key international policy documents that regulate, guide or otherwise inform CMR in the context of recent events involving international CMR during public health emergency responses, grounded in analysis of a March 2017 Chatham House roundtable event on the subject. Major thematic concerns regarding the application of existing CMR guiding documents to public health emergencies became evident. These include a lack of consideration of public health factors as distinct from a humanitarian approach; the assertion of state sovereignty vis-à-vis the deployment of national militaries; the emergence of new armed, military and security groups and a lack of consensus surrounding the 'principle of last resort'. These criticisms and gaps-in particular, a consideration for public health contexts and approaches therein-should form the basis of future CMR drafting or revision processes to ensure effective, safe, and sustainable CMR during public health emergency response.