Résumé : The decorrelation in the azimuthal angle between the most forward and the most backward jets (Mueller-Navelet jets) is measured in data collected in pp collisions with the CMS detector at the LHC at s=7 TeV. The measurement is presented in the form of distributions of azimuthal-angle differences, Δϕ, between the Mueller-Navelet jets, the average cosines of (π − Δϕ), 2(π − Δϕ), and 3(π − Δϕ), and ratios of these cosines. The jets are required to have transverse momenta, pT, in excess of 35 GeV and rapidities,