The electrochemical deposition of polypyrrole (PPy) potentiodynamically and potentiostatically over monolayers of 1-(2-thioethyl)pyrrole (1-TEP) is described. The relationship between monolayer oxidation and PPy growth depended strongly on the electrolyte. In propylene carbonate/LiClO4, the PPy polymerization potential was higher than that for 1-TEP monolayer oxidation, and the monolayer oxidation peak was identical to that seen in monomer-free electrolyte. In water/LiClO4, the oxidation and polymerization potentials were almost the same, with the result that the onset of polymerization was prevented until after the monolayer oxidation process had been completed. In water/(sodium dodecylbenzenesulfonate), an anionic surfactant, the PPy polymerization potential was lower than that in water/LiClO4, and polymerization apparently occurred without monolayer oxidation. In all cases, PPy growth was found to be essentially the same on 1-TEP, oxidized 1-TEP, and clean gold as evidenced by cyclic voltammograms, chronoamperograms, and film appearance. These results show that the 1-TEP monolayers probably decomposed before PPy polymerization began or were, in the case of sodium dodecylbenzenesulfonate, most likely inaccessible because they were covered by the surfactant. This indicates that 1-TEP cannot be used to covalently bind Pgr to gold. These results also demonstrate that the general approach to adhesion promotion through the use of thiol-modified pyrroles has conditions and limits that must be recognized. The electrochemistry of PPy grafting to surface-bound pyrrole depends critically on the electrolyte, which is important for application of this technique in real devices. In addition, the oxidation reactions undergone by such a monolayer cannot be assumed to be different in the absence and presence of pyrrole. Finally, the technique will probably not work with surfactant anions, which are of most practical interest.