The polypyrrole (PPy) films were electrochemically deposited on gold substrates with dominant crystalline orientations of (1 1 1) and (2 2 0), respectively. The results indicated the redox behavior and the corresponding complex occurring and forming, respectively, on the gold substrate in 0.1 M KCI in oxidation-reduction cycles (ORC) were strongly sensitive to the crystalline orientation of substrates, Moreover, the surface-enhanced Raman scattering (SERS) intensity of PPy deposited on gold with a dominant (1 1 1) orientation is three fold higher than that of PPy deposited on gold with a dominant (2 2 0) orientation.