High strength steels can be produced by austempering of Si-containing steels. High toughness and good wear resistance are properties possible to achieve. Surface hardening of this group of steels can give an additional increase of the surface hardness and wear resistance. Laser surface hardening has been used in order to increase the surface hardness of the steel 55Si7. The effect of surface hardening on the ferritic-austenitic carbide- free microstructure created for this steel has been studied. Optical as well as scanning electron microscopy has been used in the characterization of the micro-structural changes.