Miniemulsion polymerization has been traditionally used to synthesize latex particles with a high homogenization energy to prepare an oil/water miniemulsion followed by further polymerizations. However, the exact copy of monomer droplets to latex particles depends critically on emulsion formulation, homogenization condition as well as the stability of the mini-emulsified droplets after homogenization. In this study, we demonstrated experimentally for the first time that one-to-one copy of monomer droplets to latex particles can be synthesized via polymerization of a miniemulsion prepared from a less stringent preparation process including formulation without costabilizer and low homogenization energy. The criterion to obtain narrow size distribution of monomer droplets was established by equilibration of a low energy homogenized emulsion for different keeping time and the bulk homogenized emulsion subsequently phase separated into two layers. Top layer is the polydispersed monomer-rich phase. The bottom layer is the equilibrium-stabilized monomer droplet emulsion, in which the size distribution of droplets is narrow. The equilibrium-stabilized emulsion is stable for days and subsequent polymerization exhibits nearly 100% droplet nucleation. Furthermore, the effect of surfactant/costabilizer and initiator on the one-to-one feature for the synthesis of latex particles was investigated in details. POLYM. ENG. SCI., 49:1043-1049, 2009. (C) 2009 Society of Plastics Engineers