We developed a very simple, template-free, and environmentally friendly one-step chemical synthesis route to fabricate unagglomerated polypyrrole (PPy) nanospheres. The proposed new fabrication method enables the production of size-controlled unagglomerated PPy nanospheres without the help of any supporting materials such as "hard" and "soft" templates and under mild conditions, viz., room temperature, atmospheric pressure, and no need for acid. From the theoretical calculation, we could find that our novel system was suitable to prepare the unagglomerated PPy spheres. The process is discussed on the basis the classical colloidal and microemulsion theory.