The aim of this paper is to present a comparison of the energy level schemes of Cr 3+ (3d 3 electrons) and Co 2+ (3d 7 electrons), each of ions doped, separately, in MgF 2 crystal. We report on the detailed and consistent crystal field analysis of Cr 3+ spectra in MgF 2 crystal and compare with results, previously obtained, for Co 2+ , doped in same host matrix. The results are based on application of the exchange charge model of crystal field to the calculation of crystal field parameters and energy levels of both ions doped in MgF 2 .The calculations have been performed on previously optimized geometry of MgF 2 crystal. The obtained results are compared with experimental data and discussed.