Summary of a workshop on "Open Source Intelligence and the War in Ukraine", which brought together 15 experts on intelligence and security issues with diverse experiences in academia, the private sector, and government across several Western countries. Their expertise covered: media and journalism; public administration, political science and international relations; criminology; area studies (Russia and its neighbourhood, China); cybersecurity; strategic studies and military affairs; intelligence operations and analysis. The workshop followed the Chatham House (2022) rule, according to which “participants are free to use the information received, but neither the identity nor the affiliation of the speaker(s), nor that of any other participant, may be revealed.” This summary presents the substance of discussions but does not assign points to specific participants. The content follows the overall structure of the workshop, which was divided into five sessions of 60 to 90 minutes.