Measurement of mortality and injury in conflict situations presents many challenges compared with stable situations. However, providing information is important to assess the impact of conflict on populations and to estimate humanitarian needs, both in the immediate and longer term. Mosul, Iraq's second largest city, was overrun by fighters of the Islamic State of Iraq and Syria (ISIS) on June 4, 2014. In this study, we conducted household surveys to measure reported deaths, injuries, and kidnappings in Mosul, Iraq, both during the occupation of the city by fighters of ISIS and the months of Iraqi military action known as the liberation.