The Scholarly Article on Security Sector Reform (SSR) was produced as part of the project “Whole-of-Society Conflict Prevention and Peacebuilding” (WOSCAP). It analyses the European Union Assistance Mission (EUAM) in Ukraine which is conceptualised as a civilian security sector reform initiative. Given the tensed security environment in which this mission is being undertaken, by analysing EUAM, this article hopes to contribute to an enhanced understanding of the unique challenges faced by EU-SSR endeavours in Ukraine and draw a broader set of lessons relevant for the EU’s future SSR. The article is based on the primary and secondary data collected as part of the WOSCAP project. Its analysis is guided by the ‘whole of society approach’ to conflict prevention and peacebuilding.