The development of light weight steel structures in seismic area as Italy requires the upgrading of National Codes. To this end, in the last years a theoretical and experimental study was carried out at the University of Naples within the research project RELUIS-DPC 2010-2013. The study focused on "all steel design" solutions and investigated the seismic behaviour of strap braced stud shear walls. Three wall configurations were defined according to both elastic and dissipative design criteria for three different seismic scenarios. The lateral in-plane behavior of these systems were evaluated by 12 tests performed on full-scale CFS strap-braced stud wall specimens with dimensions 2.4 m x 2.7 m subjected to monotonic and reversed cyclic loading protocols. The experimental campaign was completed with 17 tests on materials, 8 shear tests on elementary steel connections and 28 shear tests on strap-framing connection systems. On the basis of the experimental results, and taking into account the AISI S213 provisions, behaviour factors were evaluated. This paper provides the main outcomes of the experimental tests on walls and behaviour factors evaluation.