This study describes the current state of play and historical context of intergovernmental cooperation through the Council of the Baltic Sea States (CBSS) and its engagement with civil security. It addresses the organizational, institutional, and cultural frameworks of the CBSS, as well as the international context within which it is embedded. This provides an important backdrop for describing the civil security system, which the CBSS has fostered for over 20 years. Beginning with the establishment of an expert group on nuclear and radiological safety in 1992, the CBSS now participates in a wide range of cooperative endeavours, such as information exchange on forest firefighting and environmental pollution. This study also assesses CBSS civil security along three indicators that highlight the extent to which the system is effective, efficient and legitimate. It is argued that the CBSS is a regional organization that finds its strength as a platform for facilitating and encouraging cooperation on civil security; however, its actual capacity as an actor in civil security area remains low.