Stainless steels are corrosion resistant steels with high chromium and nickel contents. Ferritic and stainless steels are soft, respectively ductile, and are prone to mechanical deformation and scratching during metallographic preparation. In addition, carbides can not always be retained. For a successful mechanical polish, it is suggested that - coarse abrasives for plane grinding are avoided. - fine grinding and polishing with diamond should be thorough and ensure removal of all deformation from plane grinding. - a final oxide polish with colloidal silica or alumina should be carried out to provide a deformation free surface. A four step procedure, completed on automatic preparation equipment, gives good and reproducible results. Stainless steels are difficult to etch chemically and the recommended etchants are very corrosive and require careful handling. Alternatively, electrolytical polishing and etching is recommended, which gives a deformation free surface, but does not retain carbides.