B-physics overview in ATLAS

An overview of the ATLAS B-physics trigger and offline performance studies is presented. From the initial running at low luminosity at LHC, high-statistics B analyzes 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 meson system the expected ATLAS sensitivities 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 continue its search for the rare B decays using the high luminosity running.