The behavior of reinforced concrete (RC) beams strengthened in flexure with Near Surface Mounted (NSM) carbon fibre reinforced polymer (CFRP) composites strips is theoretically, experimentally and numerically investigated in this paper. The specimens were tested in bending, under monotonic loading up to failure. Compared to the control specimens, the beams strengthened by NSM technique have shown a maximum increase in bending moment capacity of 220% and a mid-span deflection decrease up to 49%. The validity of the experimental results has been checked analytically and by numerical modeling, using the finite element (FE) computer software ANSYS.