A rigorous method is presented to compute the vector diffraction pattern of microscope objectives considering on-axis aberrated and radially polarized wavefronts. For that, the diffraction pattern of the microscope objective is computed considering the polarization and the wavefront at the exit pupil of the optical system. These computations do not assume that at the exit pupil of the microscope objective the wavefront is spherical but aberrated. Examples of real microscope objectives’ performance are presented.