W and Z production measured using the ATLAS detector, and impact on parton densities of the proton

Measurements of W and Z production cross sections in proton proton collisions are sensitive to parton distribution functions. The present status of the cross section measurements in the electron and muon decay channels is presented. The results are based on the full data set taken with the ATLAS detector in 2010. They are compared to theoretical calculations using different sets of parton distribution functions.