Although conventional I-section plate girders are widely used, they are still considered as open section girders; thus, lacking the adequate torsional stiffness. This causes them to be vulnerable to fail due to lateral torsional/distorsional buckling. One of the methods of improving that torsional stiffness is to turn the cross-section into a closed one. Although it is common in literature to replace the flat flanges with tubular ones, another approach is followed herein through adding additional web to the girder. Therefore, a numerical study is conducted in this research, using Ansys Workbench, to investigate the shear behaviour of transversely stiffened dual web plate girders (DWPGs). In the adopted finite element (FE) model, each of initial geometric imperfections, geometrical and material nonlinearities are taken into account. A parametric study is carried out on simply supported DWPGs involving stiffeners arrangement, web panel aspect ratio and web spacing. It is found that equipping the DWPGs with inner stiffeners between their dual webs is preferable to outer stiffeners. Particularly, DWPGs with inner stiffeners have higher shear strength and ductility compared to other DWPGs.