Modified electrode based on combination of different conductive polymers (Polyaniline - Poly(3-methylthiophene) - Poly(3,3' diaminobenzidine) (PANI - P3MT - PDAB)) was previously synthesized in dichloromethane containing HClO(4) and tetrabutylammoniumperchlorate (TBAP) supporting electrolyte. In this study, determination of hydroquinone (HQ) with amperometric I-t method over this modified and its homopolymers coated electrode was successfully carried out in river water as real sample and in solution consisting of NaHSO(4)/Na(2)SO(4) (pH 2.0). For this method, potentials between 0.45 V and 0.65 V were applied and the best analytical response was obtained at 0.55 V using this modified electrode when compared its homopolymer. The limit of detection (LOD), limit of quantification (LOQ) , the linear dynamic range and regression coefficient (R(2)) were found as 1.31 x 10(-4) mM, 4.37 x 10(-4) mM, 4.37 x 10(-4)- 95.0 mM and 0.998, respectively. These results were compared to homopolymers coated and uncoated Pt electrodes. For checking on the accuracy of the developed method and the matrices interference, determination of HQ was performed in artificially contaminated river water samples with HQ concentration 5.0 mM and 10.0 mM using this modified electrode and recovery values were calculated as % 100.6 and % 100.1, respectively.