On May 13, 2005, Uzbek government forces killed hundreds of unarmed people who participated in a massive public protest in the eastern Uzbek city of Andijan. The scale of this killing was so extensive, and its nature was so indiscriminate and disproportionate, that it can best be described as a massacre. A Human Rights Watch field investigation in Uzbekistan and Kyrgyzstan recreated a comprehensive account of the events of May 13 and 14 in Andijan. Our findings clearly demonstrate the Uzbek government forces' undeniable responsibility for the massacre.