The latest studies on the observed Higgs-like boson performed by the ATLAS experiment in diboson channels are reported. Emphasis is given to the property measurements (mass, spin- parity, couplings) of the new boson, that are driven by these channels. Most of them exploit the whole data sample of 20.7 fb−1 collected at the LHC in 2012 at \sqrt{s} = 8 TeV and 4.8 fb−1 collected in 2011 at \sqrt{s} = 7 TeV.