One-pot preparation of poly(amino naphthalene sulfonic acid) and silver nanoparticles (PANS-AgNPs) has been successfully performed in acidic aqueous condition. Using ANS monomer as a reductant and a particle stabilizer, the reduction of silver ions and polymerization of ANS occurred simultaneously in the absence of a commonly used reducing agent and initiator. Sulfonate group present in the PANS polymer acts as self dopant for polymer and a stabilizing agent. The produced PANS-AgNPs nanocomposite was characterized by UV–Vis spectroscopy and Fourier transform infrared spectroscopy. AgNPs showed its SPR band at 450 nm. AFM image revealed that AgNPs formed along with the PANS with an average particle diameter of 5 nm. The presence of AgNPs-PANS nanocomposite was analyzed by using cyclic voltammetry