The main variable was thesurface preparation method i.e. condition after casting, grinding, polishing and vibro-abrasive machining.The tests showed that the surface condition directly after casting is not suitable for galvanic plating. It is a result of pores and contamination having negative influence on the properties of galvanic coatings connected mainly with adhesion reduction. The tests performed on the polished casts also showed a low suitability of that type of initial machining for plating the magnesium alloys. After process, number of surface defects and contamination on the surface of the polished elements were noticed. The third type of machining involving grinding the cast surfaces, regarding quality of galvanic coatings, was better than previously discussed ones. However, it also showed essential defects. They resulted mainly from the process unrepeatability and possible removal of the skin layer, which uncovered internal porosity of casts.