This study examines the flexural behaviour of hollow reinforced concrete (RC) beams experimentally, numerically, and analytically. The experimental work was accompanied to study the influence of internal concrete hollow core size on the flexural response of RC beams. A control beam with a solid section and three other specimens having a hollow core area of 3%, 7%, and 10% of the beam cross-section area were tested. During loading, the crack patterns for all the specimens were recorded. The results indicated that using less than 10% of the beam cross-section as the hollow part didn’t considerably affect the failure load of the RC beams. In conclusion, the concrete core didn’t contribute to the capacity of the RC beams; however, it affected the cracking pattern, i.e. size and height. A numerical model was implemented using ABAQUS to simulate the behaviour of the hollow RC beams. The numerical model accurately expected the response of the tested RC beams. Using the validated model, a parametric study was complemented to study the influence of the hollow size and location on the RC beam response.