  Full O(alpha) electroweak corrections for gamma-gamma-> W+W- are calculated
including virtual corrections, soft and hard real photon and Z-boson emission.
The corrections are quite large ranging from -2.5% at 500 GeV to -18% at 2 TeV,
|cos\theta^\pm| < cos(10^\circ). Contributions from real photon and Z-boson
emission are important at high energies where they partly cancel large negative
contribution originating from virtual bosonic corrections. Precision
measurements that intend to uncover physics beyond the standard model must
necessarily make use of the full standard model predictions including O(alpha)
corrections.
