The EPR powder spectra of Gd3+ doped LaAlO3 are simulated for a number of temperatures between 4 and 800 K by means of the usual spin-Hamiltonian. Values are found for the zero field splitting parameters B(n, 0) only, which agree with single crystal measurements. For an accurate simulation of the axial powder spectra a variable linewidth has to be introduced, because an inhomogeneous broadening of the resonances in the xy plane is observed. This broadening is successfully described by a variable B(2, 2) parameter. This indicates that the Gd3+ ion does not fit within the LaAlO3 lattice, because GdAlO3 is not isostructural with LaAlO3. Crystal field calculations support this assumption.