Corrugated web beams are an alternative to steel girders with flat webs. They consist of a welded Isection with a thin-walled trapezoidally corrugated web and flanges made of wide flat steel. In comparison with hot-rolled or welded I-beams with flat webs, corrugated web beams offer significant material savings and are produced fully automated. Assuming the same load-bearing capacity, corrugated web beams are lighter than those with a flat web, since the corrugated web beams can often be loaded up to their plastic resistance without reinforcement of the web. Research on the loadbearing behaviour of corrugated web beams without web openings is well-established. However, the resistance of corrugated web beams with reinforced web openings, which are necessary for installations in buildings, has not been well investigated experimentally yet. This paper examines the shear force resistance of trapezoidally corrugated web beams with reinforced square web openings. Two beam-like specimens with the same geometry but differently reinforced web openings were tested. The experimental results are compared with a Finite Element Analysis using Abaqus® and with an analytical model that allows a simplified calculation. The comparison identifies how the wall thickness of the web opening reinforcement affects the shear force resistance of perforated corrugated web beams.