The lifting hook is one of the vital components in material handling systems, since sudden accidents are unavoidable if the working reliability of the hook is poor. In this study, computer-aided single hook modeling is done in accordance with the DIN 15401 standard then extensive stress analyses at different sling sizes and angles and stress analyses when the hook is rigged by sling legs with unequal leg length and rigged by sling legs with unequal leg length and height have been conducted in order to reveal the effect of sling size and angle and different rigging manners on the safety factor of the lifting hook by using finite element simulation. Loads carried by each sling member are calculated and presented. Curved beam theory and simplified theory are employed to compare finite element simulation results. The critical sling angle at which the safety factor reduces evidently has been determined by altering the sling size and angle. The critical sling angle is found to be 51 degrees, since reduction in the safety factor originates from a 51 degrees sling angle.