For flexibility of accommodating building service plants, openings are often introduced to the web of steel beams which affects the structural behaviour of the beams. The available design methods developed only for the ambient temperature situation. This paper is concerning with the effect of web opening in the ultimate shear capacity of the web panel at elevated temperature. The investigation will include the plate girders web panel containing centrally circular or square holes. In order to provide accurate assessment to the shear load carrying capacity of plate girder web panel with openings, a finite element model was established with both material and geometrical non-linearity by using ANSYS software package. Accuracy of the model is assessed by applying it to plate girders tested earlier by other researchers. Comparison of analytical results with the available experimental results for yielding patterns, ultimate load values and load–deflection relationships show good agreement between the finite element and experimental results thus validating the accuracy of the proposed model. A parametric study is undertaken to gain additional insight into the overall behaviour, failure modes, and deformation capacity for circular and square shapes of web panel openings with various sizes at elevated temperature. From these analyses, it is concluded that, variation of the ultimate shear capacity of plate girders with respect to the size of openings for girders with circular or square openings dropped continuously with increasing the temperature and the size of opening; and the drop in load carrying capacity increases significantly as the temperature increase and the opening size gets larger in size. Finally, an equation based on the results of numerical finite element analyses proposed to anticipate the reduction of the ultimate shear force due to circular or square opening size.