The subject of the study concerns the enhancement of corrosion and wear resistance of nitrided 42CrMo4 steel by the formation of zinc phosphate top layer. The present work is aimed at the assessment of the effect of increasing thickness of nitrided layer from approximately 2 µm to 16 µm on the morphology and properties of zinc phosphate coating. XRD analysis showed that along with the increase in the thickness of the nitrides layer, a change in the phase composition was observed. SEM/EDS examination revealed that top layer consists of crystalline zinc phosphate coating. The shape and size of crystals does not significantly depend on a thickness of nitrides layer but corrosion resistance determined by potentiodynamic method in 0.5M NaCl increased with an increase of thickness of a “white layer”. Similarily the wear resistance determined by the 3-cone-roll test was also the highest for 16 µm nitride layer.