Results are presented on spectral and magnetic studies of the newly synthesised Ni(II) complexes of the general formula NiL₂X₂ (L identical to acetone 1-naphthoylhydrazone, X identical to Cl, Br, NO₃, NCS). Atoms of the first coordination sphere around the Ni(II) are identified on the basis of the IR spectral data. These data, together with those on electronic spectra and magnetic measurements, suggested an octahedral coordination of Ni(II) in these complexes. Values of the crystal-field splitting parameter 10Dq served to calculate energies of the E_g and T_2g levels. Also, values of the orbital population on Ni(II) were calculated and, on the basis of these, the effective values of the ionisation potentials H_dd are determined. The most probable scheme of MOS for these complexes is proposed.