Abstract: A comprehensive model of in situ polyaniline film coating on mylar under the influence of aniline polymerization parameters is proposed. This is achieved by studying hydrochloric acid concentration, ammonium peroxydisulfate to aniline molar ratio and initial mixture temperature influence on both polymerization and the resulting polyaniline films. Polymerization was investigated mainly using solution calorimetry, while polyaniline films were characterized by UV-vis spectrophotometry. Hydrochloric acid concentration affects polyaniline film coating by controlling induction period duration for growing site formation and polymerization period duration for polyaniline chain propagation. Ammonium peroxydisulfate to aniline molar ratio affects coating by controlling growing site formation and polyaniline chain propagation intensity. Temperature affects coating by controlling overall polymerization duration. Reaction intensity and periods duration controlled by level of these parameters dictate growing sites adsorption onto mylar and polyaniline film growth. The model shows that polyaniline film coating is optimized towards bulk polymerization stoichiometric condition and is expected to qualitatively predict how a film property changes when a certain parameter is altered.