RPC hit contribution to CMS muon reconstruction at LHC

The Resistive Plate Chambers (RPCs) are used as dedicated trigger detector in the both barrel and endcap regions of the CMS experiment together with Drift Tubes and Cathode Strip Chambers. The redundancy of the muon system of CMS is used also to improve the muon identification and reconstruction efficiency. We will describe the performance of the contribution of RPC hits in the muon identification and how they complement the main muon tracking devices.