 This study investigates the relationship between the magnetic behavior of granites in northern Portugal and the redox conditions during magma genesis, with the goal of understanding the occurrence of mineralizations such as W, MO. The magnetic mineralogy of three post-tectonic plutons in northern Portugal was characterized and compared to other post-tectonic variscine plutons. The results indicate that granite areas where magnetite and or magnetite slash ilmenite coexist are important targets for W, MO, mineralizations, and that a few plutons have granites with a complex redox history leading to the formation of magnetite and ilmenite. This article was authored by C. Cruz, H. Santoveia, and F. Narona.