A measurement of the production cross-section for Z bosons that decay to muons is presented. The data were recorded by the LHCb detector during pp collisions at a centre-of-mass energy of 7 TeV, and correspond to an integrated luminosity of 1.0 fb1. The cross-section is measured for muons in the pseudorapidity range 2.0 < < 4.5 with transverse momenta pT > 20 GeV/c. The dimuon mass is restricted to 60 < M+ < 120 GeV/c2. The measured cross-section isZ+=76.0±0.3±0.5±1.0±1.3pb$$ {\sigma}_{Z\to \mu }{+}_{\mu }-=\left(76.0\pm 0.3\pm 0.5\pm 1.0\pm 1.3\right)\mathrm{p}\mathrm{b}
