Performance of primary vertex reconstruction in proton-proton collisions at $\sqrt{s}=$7 TeV in the ATLAS experiment 2010 Performance results of the primary vertex reconstruction of the ATLAS experiment in proton-proton collisions at a centre-of-mass energy of 7 TeV are presented. The primary vertex coordinate distributions, constrained by the beam-spot position and size, are shown. The position resolution is assessed using a data-driven method. INTNOTEATLASPUBL