This paper presents both experimental and numerical studies on the flexural performance of reinforced concrete beams having hexagonal (castellated) web openings. At first, a parametric study using ABAQUS program has been conducted on the governing parameters of the castellated beams. The studied parameters were the percentage of longitudinal main steel, the configuration of the reinforcing steel around the castellation, and the effect of providing side reinforcement above and below the castellation. Based on the results of the parametric study, the best configuration of the reinforcing steel around the castellation was selected based on the manifested flexural behavior. Thus, the test specimens to be tested experimentally were configured. One solid beam and another castellated beam have been tested under the effect of incremental concentrated load at the mid-span point. The obtained responses along with the mode of failure from the experimental test are compared with the predicted ones from the numerical simulation. Comparison shows good agreement between the displayed mode of failure, ultimate capacity and the developed mid-span deflection obtained from both numerical simulation and the experimental tests.