The spin Hamiltonian parameters of 55Mn2+ in cubic ZnS have been determined by means of EPR and central-ion ENDOR, using Ka-band (35 GHz) microwaves. For the first time a value for the spherical electric quadrupole interaction of Mn2+ incorporated in a single crystal has been found. Also the ligand hyperfine interaction and the electric quadrupole interaction of the twelve Zn67 nuclei nearest to Mn2+ have been determined by means of ligand ENDOR.