Thermophoresis has a direct impact on the amount of particulate deposition on the substrate due to the temperature gradients present near the substrate in a chemical vapor deposition reactor. The effect of thermophoresis on the particle transport and deposition in the reactor is predicted and verified experimentally. Different particle concentrations and sizes are considered. In addition, the motion of these particles according to the thermal gradients in the reactor is examined. The numerical and experimental results show that the particle deposition on the wafer decreases exponentially as the wafer temperature increases or the showerhead temperature decreases.