Commissioning of the Particle-flow Event Reconstruction with the first LHC collisions recorded in the CMS detector

The first collisions delivered by the Large Hadron Collider at CERN at a centre-of-mass energy of 900\,GeV, and recorded by the CMS detector in December 2009, are used to commission the particle-flow event reconstruction algorithm. The efficient reconstruction and identification of photons, electrons, charged and neutral hadrons, made possible by the versatility of the CMS apparatus, are shown to perform as expected up to a high level of precision. First results on particle-based jets, missing transverse energy, isolation and tau identification are presented and confirm the performance predicted by the simulation.