A method for manufacturing a rotor with permanent magnets may include providing a central core with a desired cross-section; providing a plurality of ferromagnetic discs having a hole shaped in a complementary manner to the cross-section of the central core; stacking up the ferromagnetic discs around the central core to form a cylindrical structure with a longitudinal cavity, wherein the longitudinal cavity is formed by the holes of the stacked-up ferromagnetic discs; integrally blocking together the stacked-up ferromagnetic discs; and removing the central core. A rotor may be manufactured by the method. The rotor may be used in an electric motor.