ATLAS tracking results from the first collision data-taking period

he first collision data taking period at the LHC at $\sqrt{s}$ = 900 GeV in November and December 2009 provided stringent tests of the ATLAS track reconstruction. The detailed understanding of the performance of the track and vertex reconstruction chains has been an integral component of the first charged particle distribution measurements in proton-proton collisions published by the ATLAS collaboration. The excellent description of the data by the ATLAS Monte Carlo simulation for track quantities and the reconstruction of weakly decaying particles is shown.