The aim of the analysis was to estimate the unit cost and to identify the key of trachoma prevalence surveys conducted as part of Global Trachoma Mapping Project (GTMP). In-country and global support costs were obtained using GTMP financial records. In-country expenditure was analysed for 1,164 districts across 17 countries. The mean survey cost was $13,113 – $17,566 per evaluation unit or $692 per cluster. Survey unit costs varied substantially across settings and were driven by parameters such as geographic location, demographic characteristics, seasonal effects and local operational constraints. The findings can aid planning and budgeting for future trachoma surveys required to measure the impact of trachoma elimination activities. Furthermore, the results of this study can also be used as a cost basis for other disease mapping programmes, where disease or context-specific survey cost data are not available.