Within the body of research aimed at improving the photovoltaic performance of quantum dot-sensitized solar cells (QDSSC), poly-3-alkyl thiophenes have been commonly used in hybrid photovoltaic devices. The roles of poly(3-hexylthiophene) (P3HT) and of poly(3-octylthiophene) (P3OT) on hybrid QDSSC were investigated in the present work. To this end, CdS and ZnS QDs were deposited by successive ionic layer adsorption and reaction method on TiO2 mesoporous film. The polymers were added by drop-casting method giving the configurations TiO2/CdS/ZnS/P3HT and TiO2/CdS/ZnS/P3OT. Results showed that the polymer covers the TiO2/CdS/ZnS surface enough to protect it from contact with the polysulfide electrolyte, while electrochemical impedance spectroscopy measurements indicated that when P3HT and P3OT were employed, the recombination resistance increased and the transport resistance decreased, causing the improvement of the open circuit voltage and fill factor, respectively.