This file compiles a comprehensive database of 485 pumping tests performed in crystalline aquifers within a single region (Brittany, France; 27,209 km²). The database currently includes 485 transmissivity and hydraulic conductivity values, as well as 195 storage coefficients, accompanied by associated metadata. This framework will be progressively expanded to cover the entire Armorican Massif. This dataset supports the scientific article published in Journal of Hydrology: Regional Studies: Boisson, A., Lucassou, F., Schroëtter, J.-M., Boivin, B., Aertgeerts, G., Venville, M., de Dreuzy, J.-R., Abhervé, R., Armandine Les Landes, A., Rouxel, E., Idée, E., & Mougin, B. (2026). A database of pumping tests in crystalline rocks: Lithostratigraphic controls on transmissivity and its log-normal distribution (Armorican Massif, France). Journal of hydrology: Regional Studies. https://doi.org/10.1016/j.ejrh.2026.103406 This work provides a quantitative and comparative assessment across 27 distinct crystalline rock settings, offering new insights on lithostratigraphic controls on transmissivity variability. The database constitutes a valuable resource for numerical modeling, geothermal potential mapping, and comparative hydrogeological studies across different crystalline terrains. Geographical regionArmorican Massif, Brittany, France