Several water-soluble polymers were used as templates for the in situ polymerization of pyrrole to determine their effect on the generation of nanosized polypyrrole (PPy) particles. The polymers used include: polyvinyl alcohol (PVA), polyethylene oxide (PEO), poly(vinyl butyral), polystyrene sulfonic acid, poly(ethylene-alt-maleic anhydride) (PEMA), poly(octadecene-alt-maleic anhydride), poly(N-vinyl pyrrolidone), poly(vinyl butyral-co-vinyl alcohol-co-vinyl acetate), poly(N-isopropyl acrylamide), poly(ethylene oxide-block-propylene oxide), hydroxypropyl methyl cellulose, and guar gum. The oxidative polymerization of pyrrole was carried out with FeCl3 as an oxidant. The morphology of PPy particles obtained after drying the resulting aqueous dispersions was examined by optical microscopy, and selected samples were further analyzed via atomic force microscopy. Among the template polymers, PVA was the most efficient in generating stable dispersions of PPy nanospheres in water, followed by PEO and PEMA. The average size of PPy nanospheres was in the range of 160 nm and found to depend on the molecular weight and concentration of PVA. Model reactions and kinetics of the polymerization reaction of pyrrole in PVA were carried out by hydrogen 1H NMR spectroscopy using ammonium persulfate as an oxidant. (C) 2012 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 50: 4966-4976, 2012