The aim of this work is to utilize nano-fluid particles (Titanium dioxide, TiO2) to enhance the heat transfer characteristics of the Heat Transfer Fluid (HTF) of the solar heating system to improve its thermal performance. It is found that using the nano-fluid particles like TiO2 improves the heat transfer characteristics of the HTF of the solar water distillation system and consequently increases the rate of daily water productivity. It is found also that the system can produce distilled water of 5.616 m3/day, 6.048 m3/day, 6.134 m3/day, and 7.128 m3/day in case of using TiO2 with a concentration of 0 mg/l, 75 mg/l, 80 mg/l, and 100 mg/l respectively. The experimental pilot unit was installed in Solar Energy Department, National Research Centre, and Giza, Egypt. Several test runs are performed to measure all assigned parameters that affect the system performance. The tested system can positively contribute in water desalination units, especially in rural and isolated communities.