This　paper　investigates　the　resistance　of　micropitting　on　two　materials,　using　an　FZG　back-to-back　test　rig　with　CPT　gears.　The　materials　are　wrought　steel　(16MnCr5)　and　a　commercial　powder　metallurgical　material　(AstaloyTM　Mo).　Two　finishing　methods　were　studied:　grinding　and　superfinishing.　Experimental　results　show　that　the　superfinishing　prevented　micropitting,　but　led　to　premature　failure　due　to　cracks　in　the　root　caused　by　tip-to-root　interference.　Micropitting　was　initiated　at　a　higher　load　stage　for　the　powder　metallurgical　steel　compared　to　the　ground　wrought　steel.　The　failure　mechanisms　were　similar　between　materials　with　the　same　surface　finish.　The　powder　metallurgical　steel　showed　subsurface　initiated　fatigue　compared　to　the　wrought　ground　steel　having　surface-initiated　fatigue.　Testing　new　finishing　methods　and　materials,　one　has　to　be　aware　of　the　influence　of　the　gear　micro　geometry.