Low frequency noise measurements have been performed on Al-Si resistors, subjected to high current density (j = 2 x 10(6) A/cm2), in order to investigate the dependence of the electromigration noise on the structural and geometrical parameters. To this end five groups of samples have been used, each characterized by a different value of the average grain size D. The power spectral density S(v) of the voltage fluctuations across the samples has been measured using test patterns with different widths w and lengths l. It has been found that S(v) shows an exponential dependence on the grain dimension and a linear dependence on the shape factor F = l/w. The model previously proposed for noise generation has been integrated to take into account the observed dependence of S(v) on D and F.