This paper is concerned with the ultimate load behavior of thin-webbed steel plate girders with inclined stiffeners. Non-linear analyses were carried out on the simply supported plate girders using a commercial finite element code, LUSAS. The girders are of practical size and subjected to a single concentrated load applied at the centre of gravity of the section. Effects of inclination degree of stiffeners and central web openings on the performance and behavior of such girders are investigated. Variations of ultimate strength, buckling characteristic and load-deflection response are obtained. The ultimate strength is found to increase significantly when the inclined stiffeners were provided to the girders, regardless the effect of openings in the web.