Steel beams are susceptible to flexural buckling, torsional-flexure buckling due to various types of loading and support conditions. This paper presents an investigation of the effect of stiffeners on the load-carrying capacity and the deflection resistance of thin-walled steel I-beams under various load conditions. The modeling of beams was carried out using Hypermesh tool and then it was analyzed by using the ANSYS software package. The support condition adopted for the study is the cantilever condition along with the loading conditions of concentric point load, torsional moment and eccentric point load. The dimensions of the I-beam as well as the thickness of the stiffener plate were kept constant throughout the study. A total of four patterns have been studied, the patterns are single and double vertical, single and double horizontal stiffener arrangement. The result was compared with respect to the conventional one without any stiffener. The transverse and axial deformation, the equivalent and axial stresses of beams are studied along with the mode of failure and effect of bending and torsion. It is observed that the use of HYPERMESH software and ANSYS software resulted in much easier modeling, faster and cost-effective analysis for the thin-walled steel beam sections without any destructive methods.