The steel plate shear wall systems have some advantages in resisting seismic forces. Among the most important are the good dissipation capacity and initial stiffness. Unfortunately, there are no significant applications of this new structural system in Europe, partly due to the lack of design provisions in the seismic code EN1998-1. The paper addresses the seismic performances of steel plate shear walls. Non-linear dynamic analyses are employed using different ground motions. Values of the behavior factor q are proposed. Acceptance criteria and numerical modeling are based on an experimental program conducted in the Laboratory of Steel Structures from the ‘Politehnica’ University of Timisoara.