We present a combined study of the growth, structure, and related magnetic properties of Fe/W(001) using low-energy electron diffraction, scanning tunneling microscopy, the magneto-optic Kerr effect, and scanning electron microscopy with polarization analysis. Different growth regimes arise due to a competition between the stress-related elastic energy and diffusion barriers. By increasing the growth temperature, diffusion mechanisms may be switched on, activating more and more diffusion paths that lead to a reduction of the elastic energy stored in the growing films. This results in strong variations of the structure and morphology of the films. The influence of each structural and morphological phase of the Fe films on the magnetic properties can be observed and is interpreted within micromagnetic theory.