In this Letter the complete two-loop corrections to the Higgs-boson decay,
441203547aa3"" title=""Click to view the MathML source"">H→γγ, are presented. The evaluations of both QCD and electroweak corrections are based on a numerical approach. The results cover all kinematical regions, including the
WW normal-threshold, by introducing complex masses in the relevant (gauge-invariant) parts of the LO and NLO amplitudes.