W/Z Production at ATLAS

Due to their large cross-sections the W and Z bosons are widely produced at LHC and they are the highest source of high-pT leptons. These two characteristics make them suitable for many purposes, from the very fist stages of the data taking to the high luminosity scenarios. In this talk is shown how they can be used to assess the detector performances and how it's possible to measure their cross-sections with a percent level experimental uncertainty with 100 pb-1 at 7 TeV center of mass energy. Finally the impact of the PDF theoretical uncertainties on the cross-section measurements is taken into account and a method to improve the PDF knowledge at low-x using W charge asymmetry is presented.