This paper presents one of the latest nature-inspired meta-heuristics algorithms known as Cuckoo Search Algorithm (CSA) to solve optimal capacitor placement and sizing (OCPS) problem in radial power systems for the purpose of maximizing annual net saving by reducing the power losses with the acceptable voltage ranges. In the proposed algorithm, discrete nature of the capacitors is considered. Forward and backward sweep (FBS) algorithm is applied for computing power losses and bus voltages. To show the superiority and effectiveness of proposed CSA in solving OCPS problem, standard IEEE 9 bus radial distribution system is used. The obtained results are compared with other methods in literature and the contribution in terms of the quality of solution is reported.