Abstract: Mercury is a natural occurring element and present in various concentrations in natural gas. Mercury is not only hazardous to human health and the environment but could also attack equipment components resulting in mechanical failure and gas leakage. This paper describes the preparation of various sizes and shapes of Au nanoparticles for mercury adsorption by using a microwave (MW)-polyol method in the presence of different polyvinylpyrrolidone (PVP) concentrations (1.9, 3.8 and 5.7 mM) as a polymer surfactant. Mixtures of spherical, triangular, hexagonal, octahedral, decahedral and icosahedral particles were obtained using this rapid method. Sizes and shapes was found strongly depend on the concentrations of PVP. Large spherical particles were the major product of PVP concentrations (1.9 and 3.8 mM), whereas small spherical particles were preferentially produced at the highest PVP concentration (5.7 mM). It should be noted that the polygonal particles also increases with increasing PVP concentrations. The amount of mercury adsorbed using 10 ppm mercury solution is the highest (7.2%) for PVP concentration of 5.7 mM. It is concluded that PVP concentrations affects the formation of sizes and shapes of Au nanoparticles thus affects the mercury adsorption. The present result provides new information about mercury adsorption on Au nanoparticles.