Summary The presented work deals with the synthesis and thermal characterization of TiO2 filled Polycarbonate/Polystyrene (PC/PS) blend nanocomposites. Nanoparticles of Titanium‐dioxide have been synthesized by simple chemical method. Average grain size of as prepared nanoparticles have been determined by both TEM and XRD. Titanium‐dioxide Filled Polycarbonate/Polystyrene blend nanocomposites have been prepared by solution casting method. The XRD pattern and FTIR spectrum confirm the formation of blend nanocomposites. Differential Scanning Calorimetry (DSC) has been used to study thermal properties. The DSC thermograms indicate that the glass transition temperature and hence thermal stability of nanocomposites enhances with addition of filler content.