The rare decay B→Xsγ

The next-to-leading-order (NLO) analysis of the decay B --> X(s)gamma is reviewed in this talk. The theoretical framework and the various ingredients for a theoretical prediction of the branching ratio Br(B --> X-s gamma) are briefly outlined. The numerical analysis focuses on an estimate of the theoretical uncertainties. It is pointed out that the theoretical error is presently dominated by parametric uncertainties that may be reduced in the future. In view of oncoming measurements at future B factories this underlines the importance of the decay B --> X(s)gamma for the search for new physics.