This Public Database on Irregular Migration Flow Estimates and Indicators, in short MIrreM D5.2, is a MIrreM project deliverable under work package 5. This database provides an inventory and critical appraisal of available estimates and indicators related to irregular migration flows. More specifically, the database contains the country-level data collected by MIrreM’s national rapporteurs, as well as EU-level data from sources other than Eurostat. The datasets include meta-level information on sources and methodology and a quality assessment based on MIrreM’s criteria. Users of this database are advised to consult the following companion document (henceforth, MIrreM Working Paper No. 9/2024) for a full discussion of the context, the underlying concepts, and the methodology used: Siruno, L., Leerkes, A., Hendow, M. & Brunovská, E. 2024. Working Paper on Irregular Migration Flows. MIrreM Working Paper No. 9. Krems: University for Continuing Education Krems (Danube University Krems). https://doi.org/10.5281/zenodo. 10702228. The MIrreM project is a follow-up to CLANDESTINO, which covered the period 2000-2007. MIrreM extends this to the subsequent period 2008-2023. The data covered in this database reflect what is available within this period. Most of the data was collected between June and October 2023, and thus in some cases, the data are only until 2022 pending complete reports for 2023.