W, Z and Diboson production at the LHC with ATLAS

W and Z bosons are produced at the LHC with a high rate and yield a clean source of high pT isolated leptons. Their study is important for understanding the performance of the ATLAS detector and allows to probe the Standard Model predictions. Measurements of the W and Z production cross sections, the W/Z cross-section ratio and the W charge asymmetry at sqrt(s) = 7 TeV with the ATLAS experiment are presented. Observations of W/Z decays to tau final states are reported. First results on the W/Z+gamma and WW di-boson final states are also discussed