In this paper, the effects of irreversible electroporation induced by rectangular long unipolar and short bipolar voltage pulses on 3D cells have been illustrated. The cells geometry was reconstructed starting from 3D images of real cells obtained using the confocal microscopy technique. A numerical model based on the Maxwell and the asymptotic Smoluchowski equations has been developed to calculate the induced transmembrane voltage and pore density on the plasma membrane of the real cells exposed to the pulsed electric field. Moreover, in the case of the high-frequency pulses, the dielectric dispersion of plasma membranes has been taken into account using the second-order Debye-based relationship. Several numerical simulations have been performed obtaining a good agreement between the numerical and experimental results.