On 9-10 December 2019, the Pugwash Conferences held a workshop in Geneva on hypersonic weapons. The meeting, organized by the Pugwash Geneva office, was held under Chatham House rules and brought together 30 participants from various regions, including current and former government officials, scientists, engineers, academics and think tank/NGO experts. It aimed at fostering a constructive exchange of views and deepening common understanding of hypersonic weapons. Participants discussed technical aspects, factors driving the development, roles and purposes of hypersonic weapons, as well as risks associated with their deployment and use.