Uniform and stable polymer protected spherical platinum, palladium, silver and ruthenium nanoparticles were synthesized using glycerol both as solvent as well as reducing agent. A comparative study was done on the mode of heating viz reflux and microwave (MW) on the size and morphology of nanoparticles. Further it was observed that the morphology of the particles varied from spherical to triangular prism in the case of palladium nanoparticles when the reaction was changed from normal mode of reflux condition to microwave mode (MW) of heating. Triangular prismatic and spherical metal nanoparticles were characterized using UV-vis spectroscopy, transmission electron microscopy (TEM) and X-ray diffraction (XRD) analysis. (c) 2007 Elsevier B.V. All rights reserved.