New Optimal Fuzzy Logic Guidance (NOFLG) law for the class of surface to air homing missile is proposed. The introduced approach is a modification of Optimal Fuzzy Logic Guidance (OFLG) law. Time Variant Particle Swarm Optimization (TVPSO) is used to optimize both Membership Functions (MFs) and rules' weights of the proposed design. The performance of the new guidance law is compared with that of OFLG one. Different case-studies show that the current approach provides better performance in regard to; miss distance, flight time and control effort.