  W and Z bosons will be produced copiously at the LHC proton-proton collider.
We study the parton distribution dependence of the total production cross
sections and rapidity distributions, paying particular attention to the
uncertainties arising from uncertainties in the parton distributions
themselves. Variations in the gluon, the strong coupling, the sea quarks and
the overall normalisation are shown to lead to small but non-negligible
variations in the cross section predictions. Ultimately, therefore, the
measurement of these cross sections will provide a powerful cross check on our
knowledge of parton distributions and their evolution.
