The effects of shock-heated flow on anatase TiO2 nanoparticles (NPs) were investigated using a pressure-driven shock tube. Two test conditions were considered that produce dissociate oxygen and nitrogen at applied temperature of about 3640 °C and 5570 °C, respectively. For the oxygen case, the weight percentages of rutile in the NPs were determined to be 43.3 and 45.9 wt% for the 10 and 15 shock pulses, respectively. In the case of nitrogen, the weight percentages of rutile in the samples were estimated to be 38.7, 46.1, and 48.3 wt% for the 5, 10, and 15 pulses, respectively. It has been shown that the grain size was imperceptibly influenced by multiple shock pulses in spite of the substantial fraction of phase transition from anatase to rutile.