B-physics overview in ATLAS

An overview of the ATLAS B-physics trigger and offline performance studies are presented. From the initial running at low luminosity at LHC, high-statistics B analyses will allow sensitive tests of possible new physics contributions by searching for additional CP violating effects and for anomalous rates of rare B-decay channels. In the physics of the $B^{0}_{s}$ meson system the expected sensitivity to mass and width differences are compared to recent measurements done at the Tevatron. There is also sensitivity to a weak mixing phase beyond the Standard Model expectation. ATLAS will also be able to access rare B decays using the high luminosity running.