Triphenylamine-based hydrazones were subjected to electropolymerization process that gave well conductive hydrazone based polymers. The first example of polyhydrazone formation during the electrochemical process was shown. The estimation of polymer structure was demonstrated using IR spectroelectrochemistry. The EPR spectroelectrochemistry allowed to explain why in some cases dimer couldn't be formed. The results of electrochemical, spectroelectrochemical investigation of small molecules, as well as their polymers obtained by electropolymerization, are presented. The comparative study of electropolymerization and doping process by IR, EPR, potentiostatic and potentiodynamic UVVis-NIR, DEIS spectroelectrochemical techniques was performed to determine the reaction path, charge carriers and conductivity of polymeric layers. (C) 2017 The Authors. Published by Elsevier Ltd.