The WZ production cross section in proton–proton collisions at s=13 TeV is measured with the CMS experiment at the LHC using a data sample corresponding to an integrated luminosity of 2.3 fb−1. The measurement is performed in the leptonic decay modes WZ→ℓνℓ′ℓ′, where ℓ,ℓ′=e,μ. The measured cross section for the range 60<mℓ′ℓ′<120 GeV is σ(pp→WZ)=39.9±3.2(stat)(syst)−3.1+2.9±0.4(theo)±1.3(lumi) pb, consistent with the standard model prediction.