The parameters affecting the reproducible electrodeposition and redox switching of films of poly-3-methylthiophene (PMT) on various substrates have been studied in three independent laboratories in order to establish a firm basis for further research on electroactive polymers. The film-forming electrodeposition of PMT was performed in acetonitrile containing 0.3 M 3-methylthiophene and 0.1 M tetraethylammoniumperchlorate. An aqueous solution of 0.1 M sodium perchlorate was used for the cycling experiments. Based on the evaluation of electrochemical data obtained from cyclic voltammetry, a parametric framework deemed necessary for comparable and reproducible studies is defined.