Electro-passivated bright and metallic finishes have been produced on cast and wrought magnesium alloys: AZ91, AM50 and AZ31. A selective etching method which allows eliminating minor surface defects by yielding textured metal appearance has been found. These techniques have also been combined with coloured anodising. As a result a variety of decorative finishes has been obtained. Designed technology offers additional routes to traditional magnesium surface treatment by formation of aesthetically attractive metal appearance. The surface films on the chemically and electrolytically polished magnesium alloys AZ31 and AZ91 have been investigated using X-ray photoelectron spectroscopy (XPS) method. Experiments show a uniform surface film in electropolishing processes and selective etching of aluminium and magnesium in chemical brightening. It was experimentally found that the nature of the surface films is different for bare, chemically polished, and electro-polished metal. All these data has been used for the experimental work on passivation of bright magnesium. As a result an efficient electro-passivation method has been designed and used in practical applications.