Scientific discoveries and technological innovations have always exerted a great influence on peace and security. New civil and military technologies are revolutionizing warfare. Particularly striking areas are cyber warfare and the rapid development of unmanned weapons systems. Issues of nuclear disarmament, missile defence or space armament as well as chemical and biological weapons are again becoming more urgent. The conference SCIENCE · PEACE · SECURITY ’19 aimed for an accurate understanding and fruitful discussions of today’s and tomorrow’s peace and security challenges. This includes scientific-technical as well as interdisciplinary contributions, focusing on problems of international security and peace-building as well as contributions dedicated to transparency, trust-building, arms control, disarmament, and conflict management.