Abstract: An optimum method based on iterative FFT algorithm for thinned linear arrays featuring an optimal peak side-lobe level ispresented and the detailed steps of the method are discussed. An optimal elements distribution can be obtained when each iterationloop starts with a different random initialization of element excitations by using the fourier transform relationship exists between thearray factor and the element excitations. Array thinning is accomplished by setting the amplitudes of the largest element excitationsto unity and the others to zero during each iteration cycle. Finally,the analysis of the simulated results confirm the quickness, theeffectiveness and the robustness of the method.