This paper presents an experimental programme designed to investigate the failure mode and ultimate capacity of pultruded glass fibre reinforced polymer (GFRP) cellular profiles subject to transverse loading. Presented in this study are the results of the characterisation of twenty six GFRP 152 × 76 × 6.4 mm I stub beams, 300 mm long. The beam specimens were categorised as plain for the control tests and those with circular or rectangular openings, centrally positioned. The specimens were subject to different loading configurations, noted as End Bearing with solid ground (EB), Interior Two Flange (ITF), Interior Bearing with solid base (IB) and End Two Flange (ETF) Results indicate a reduction in load-carrying capacity of the specimens with the opening when compared to the control specimens. The reduction was up to 20% for the specimens with circular openings and up to 25% for specimens with rectangular openings. The study revealed that loading configuration IB and ITF exhibit larger nonlinear behaviour and deformability than loading configurations EB and ETF. Various research has been conducted on its mechanical properties, connections, pultrusion techniques and web crippling behaviour of thin-walled GFRP section. Limited research can be found in the literature on the behaviour of pultruded GFRP beams with large perforation, subject to transverse static loadings.