Ni films are grown at room temperature on (i) flat and (ii) pre-nanostructured Cu(001) surfaces and studied in situ via scanning tunneling microscopy and the magneto-optic Kerr effect. In the first case, we demonstrate that controllable Ar + bombardment of 30–45 monolayer thick Ni/Cu(001) films results in the formation of self-organized pseudoperiodic nanostructures. The nanostructuring process rotates the easy-magnetization axis of the 45 monolayer Ni/Cu(001). In the second case, during the growth of Ni on pre-nanostructured Cu(001), neither preferential decoration of step-edges by material nor filling of the Cu-craters occurs. The growth mode resembles that of Ni on vicinal Cu(001) surfaces.