Mulitgram-scale products exclusively containing polypyrrole (PPy) and magnetic carbon nanoparticles (MCNPs) with uniform diameters were successfully fabricated without a size-selection process. The PPy nanoparticles (ca. 60 nm in diameter) were synthesized by micelle templating, and the MCNPs (ca. 50 nm in diameter) were obtained from the carbonizatio of an iron-doped polymer precursor. The polypyrrole nanoparticles had reasonable electrical conductivity, while the magnetic carbon nanoparicles possess a microporous structure and exhibit ferromagnetic properties at room temperature.