  The presence of tau leptons in the final state is an important signature in
searches for physics beyond the Standard Model. Hadronically decaying tau
leptons can be reconstructed over a wide kinematic range at ATLAS. The
reconstruction algorithm for hadronically decaying tau leptons and the
performance of tau lepton identification is described. A review of physics
processes with tau lepton final states is given, ranging from Standard Model
processes in early data, such as W and Z boson production, to searches for new
phenomena beyond the Standard Model.
