Polyaniline (PANI) was prepared using chemical method in the presence and absence of p-phenylenediamine (PPDA) and Ammonium peroxydisulfate (APS) was used as oxidizing agent. The effect of PPDA concentrations on the PANI films formation were monitored using quartz crystal microbalance (QCM) technique. It was found that the presence of PPDA affect the growth rate (G(r)) and the reaction time. As the PPDA concentration increases reaction time decreases and the G(r) increases. UV-VIS absorption spectra for the in situ PANI films deposited onto glass supports was used for justification the data obtained from QCM. The presence of PPDA has no effect on the structure and crystallinity of PANI and that confirmed using FTIR and X-ray. (C) 2010 Elsevier Ltd. All rights reserved.