Abstract π-π conjugated polymer polypyrrole (PPy) particles were synthesized by chemical oxidative polymerization of pyrrole (Py) monomers using H2O2 as an oxidant. No surfactants were added to the polymerization solution, therefore pure PPy particles were formed. UV–vis molecular absorption spectroscopy (UV–vis MAS) was used to monitor the Py polymerization process. The spectral properties and morphology of formed PPy particles were studied using Fourier-transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM). The influence of H2O2 and Py concentration, temperature and pH of media on the PPy particles formation rate was investigated. It was found that the polymerization solutions were unstable colloidal suspensions consisting of the PPy particles. SEM analysis revealed that PPy particles were 50–100 nm in diameter, which aggregated into larger structures of 600–1000 nm in diameter with irregular granular morphology. FTIR data showed that the molecular structure of the synthesized particles was identical to that of PPy produced by conventional methods.