Oxidative dispersion polymerization of pyrrole using ethylhydroxyethylcellulose stabilizer in water or aqueous alcohol medium yields stable dispersions of submicrometre-sized conducting spherical polypyrrole particles. Transmission electron micrograph images of the particles from the original dispersion distinguish two kinds of particles : one very small, similar to 20 nm in diameter, and the other eight to ten times larger. The former constitutes about 1% of the total mass of particles. Similar results were obtained with a poly(vinyl methyl ether) stabilized polypyrrole dispersion.