Reports suggest that up to 80 million people have been resettled due to the construction of large dams in the past century. Published resettlement data regarding large dam projects comes from different sources, with numbers that can be greatly dispersed. We have examined resettlement data for 29 large dam projects gathering and analysing up to 43 datum per dam project in our sample.We find that dispersion is influenced by the project cycle (with resettlement figures from the planning and design phase found to be lowest), the stakeholders releasing it (with resettlement figures released by project advocates lower than those of project opponents), the political regime (with highest data dispersion found in hybrid regimes and limited dispersion found both in democratic and autocratic regimes) and with time of completion (with dispersion increasing for dams completed since 2010). Our findings thus present some suggestive evidence for the political perspective within the project management literature which emphasizes the contested nature of truth and knowledge. Overall, our study highlights that data in the dam industry and resettlement data must be treated with caution. Furthermore, it provides the starting point for the development of a tool that helps to de-bias resettlement data provided for large dam projects.