Abstract A facile method to prepare polymer-TiO 2 hybrid nanocomposite based solar cells has been developed. Here a fabrication method to make the nanocrystalline TiO 2 layer from commercial TiO 2 powder using a simple approach is reported. Active layers were prepared in a thickness range from 0.3 to 1.8 μm with this method. We also demonstrate its use to obtain efficient organic-inorganic hybrid nanocomposite solar cells giving photovoltaic current density as high as 4.5 mA/cm 2 and power conversion efficiency of 0.79%. Commercially available conjugated polymers such as poly[3-(5-carboxypentyl)thiophene-2,5-diyl] (P3HT-COOH) as sensitizer, poly(3-hexylthiophene) (P3HT) as hole conducting layer and conducting poly[3,4-(ethylenedioxy)-thiophene]:poly(styrene sulfonate) (PEDOT:PSS) as charge collection layer have been used. Effect of annealing on the solar cell performance is studied in correlation to the morphology of the nanocomposite as well as absorption in active layers.