This paper proposes a hybrid method to determine the optimal locations and sizes of renewable Distributed Generation (DG) sources in radial distribution system (RDS). The proposed method is based on Moth-Flame Optimization Algorithm (MFO) and the loss sensitivity factor (LSF). The most candidate locations for incorporating of DG are determined using LSF while MFO algorithm is employed to find the optimal locations and sizes of solar (PV) and wind (WTG) based DG from the candidate buses for minimizing the power loss, improving the voltage profile and enhancing the voltage stability, simultaneously. The proposed method is tested on standard radial distribution system. The obtained results using the proposed method are compared with those obtained from different reported optimization techniques in literature. Numerical results show the superiority of the proposed method over the other reported techniques in term of the objective function. Moreover, incorporating the renewable DG optimally can enhance the system performance.