ABSTRACTIn this work we present a 1:50,000 geological map of the basement rocks of Andorra that is the harmonization of the results of two decades of field work and data analyses in the frame of the 1:25,000 Geological Map of Andorra Project by CENMA–IEA (at present AR + I, Andorra Research + Innovation). The study area lies entirely in the Axial Zone of the Pyrenees, where only late Neoproterozoic and Paleozoic rocks and Quaternary deposits crop out. The map is produced at 1:25,000 scale and Quaternary deposits have been removed, in order to obtain a continuous basement map that can be used as the basis for stratigraphical and structural works. The main results of this work are the publication of new cartographic and structural data, as well as a better understanding of the stratigraphy in this sector.