Starting on 24 February 2022, a large scale armed conflict triggered an unprecedented humanitarian crisis across all regions of Ukraine. Between March 9 and 16, the International Organization for Migration (IOM) conducted a rapid representative assessment of the general population in Ukraine to gather initial insights into internal displacement and mobility flows, and to assess local needs. While Displacement Tracking Matrix tools are being established, this general population assessment will serve as a preliminary source to identify areas with high humanitarian needs and to inform the targeting of response aiming to assist the conflict-affected population. The geographical scope of the assessment covers the entire territory of Ukraine, all five macro-regions (West, East, North, Centre, South, and the city of Kyiv), with the exception of the Crimean peninsula. The probabilistic sample, representative at macro-region level, was constructed through a random‐digit‐dial (RDD) approach, and 2,000 respondents aged 18 and over were interviewed using the computer assisted telephone interviewing (CATI) method. Those currently outside Ukraine were not interviewed. Population estimates assume that children travel together with their adult guardians. The estimates rely on the UNFPA population data for Ukraine, agreed upon as the common population baseline by the humanitarian community.