The measurement of hadronic activity recoiling against W and Z vector bosons provides an important test of perturbative QCD, as well as a method of searching for new physics in a model independent fashion. We present a study of the cross-section ratio for the production of W and Z gauge bosons in association with exactly one jet R-jets= (W+1jet)/(Z+1jet), in pp collisions at sqrt(s) = 7 TeV. The study is performed in the electron and muon channels with data collected with the ATLAS detector at the LHC. The ratio R-jets is studied as a function of the cumulative transverse momentum pT distribution of the jet. Residual systematic uncertainties are parameterized in the same pT distribution. This result can be compared to NLO pQCD calculations and the prediction from LO matrix element + parton shower generators.