Particle identification is one of the key requirements of the LHCb experiment. The ability to distinguish between pions, kaons and protons in a variety of final states is essential for the study of CP violation and rare decays of B hadrons. The particle identification system is composed of two RICH detectors, covering the full angular acceptance of the spectrometer and designed to give particle identification for the momentum range of 1 up to 100GeV/c. The two RICH detectors are based on gaseous (C 4 F 10 and CF 4 ) and aerogel radiators and an optical system of spherical and flat mirrors which focuses the Cherenkov photons onto the photon detectors planes. These are equipped with a total of 484 Hybrid Photon Detectors (HPDs). The silicon pixel detector of each HPD is read out to give a resolution on the photocathode of 2.5×2.5mm2. First experience and results from RICH commissioning and operation at the LHC will be discussed.