This research investigated experimentally and numerically the general behavior of six concrete beams reinforced with longitudinal and transverse bars made of Glass Fiber Reinforced Polymer (GFRP) or steel. Six beams were divided into three groups with different variables. The first group consisted of two beams reinforced with GFRP bars in main direction and with steel stirrups. The variable of this group was the spacing between the stirrups. The second group consisted of two beams also reinforced with GFRP bars in the longitudinal direction and with stirrups in the transverse direction. The variable of this group was the same – spacing between the stirrups. As for the third group, it consisted of two beams reinforced with GFRP bars in the longitudinal direction and without stirrups in the transverse direction. The variable of this group was the main reinforcement ratio. The results showed that the beams reinforced with GFRP bars improved their behavior, bending strength and the deflection with different ratios, but had somewhat limited shear resistance when using GFRP stirrups. All the tested beams exhibited linear elastic behavior until failure, with GFRP being more brittle compared to that of ductile steel. The numerical simulation of six beams using ABAQUS software showed good agreement with the experimental data obtained in the laboratory.