Beyond Standard Model (BSM) Physics can be searched for indirectly in processes strongly suppressed in the Standard Model, e.g. in flavor-changing neutral-current processes. Results of the study with ATLAS data of the renowned rare decay, Bs -> mu+mu-, will be presented. The measurement of the angular distribution parameters in the weak decay Bd -> K*mumu is also sensitive to BSM physics. Results with ATLAS data will be discussed in the presentation.