In this study, electrochemically roughened Au(111) is modified with underpotential deposition (UPD) silver for the first time. The formation of self-assembled monolayers of pyrrole monomers and subsequently further autopolymerization are found on the UPD-Ag-modified gold surfaces. The presence of UPD Ag improves the stability of polypyrrole (PPy) monolayers against desorption in a sonicating bath at elevated temperature. Furthermore, the nucleation and growth mechanism for PPy electropolymerized on UPD-Ag-modified Au is distinguishable from that on unmodified Au. The corresponding conductivity and the Raman intensity of PPy electropolymerized on UPD-Ag-modified Au increase by about 2-fold and 4-fold, respectively.