Data 2013 2013 A search for a Higgs boson decaying into a \Z boson and a photon is described. The analysis is performed using a dataset recorded by the CMS experiment at the LHC from proton-proton collisions at a centre-of-mass energy of 7 and 8\,TeV, corresponding to an integrated luminosity of 5.0 and 19.6\,fb$^{-1}$, respectively. Limits are set on the cross section of a standard model Higgs boson decaying to opposite-sign electron or muon pairs and a photon. The expected exclusion limits at 95\% confidence level are between 6 and 19 times the standard model cross section in the mass range of 120 and 150~\GeV, and the observed limits are between about 3 and 31 times the standard model cross section.