In situ STM imaging of Au(100) electrode in 1 MHClO4 + 0.03M aniline revealed highly ordered aniline adlattices of (2 root 2 x 4 root 2)R45 degrees and (root 10 x root 10)R18 degrees and polyaniline molecules exhibiting wiggling conformations at potentials negative and positive of 0.95 V ( vs. reversible hydrogen electrode), respectively.