The Allianz Tower was a 42-story high-rise structure serving as the headquarters of Allianz Insurance Company in Istanbul. Seismic performance of the building was evaluated considering the state-of-the-art performance codes for tall buildings. Performance assessment studies were carried out by nonlinear time history analyses. Perform3D software was chosen for the time history analyses. Results of the site-specific hazard assessment study were used for the time history analyses. Since it is known that story drifts occurring in tall buildings can damage non-structural elements, performance of non-structural elements in the Allianz Tower were checked for drift results in the time history analyses. Furthermore, business interruption analysis was also a part of the performance assessment study of the tower’s non-structural facade system.