The synthesis of titanium oxide nanoparticles (TiO2NPs) has been successfully carried out using pulsed laser ablation in deionized water to produce titanium oxide nanoparticles. This synthesis is included in the top-down method which aims to produce high-purity nanoparticles synthesis. Experimentally, an Nd:YAG laser beam (with 1064 nm, 85 mJ and 10 Hz) was focused on the surface of a high-purity (99.9%) titanium plate placed in deionized water. The high energy pulsed laser Nd:YAG laser makes the titanium plate ablate for 30 minutes. This is because the melting of the titanium plate surface causes the formation of small titanium oxide particles. When these particles hit deionized water this synthesis titanium oxide will form a colloid. Furthermore, colloidal titanium oxide nanoparticles have been successfully produced with a bluish-white color. The absorbance of TiO2NPs was shown at 239.75 nm as the appearance of colloidal TiO2NPs and the average diameter at 73.47 nm. Therefore the synthesis of TiO2NPs by pulsed laser ablation method can produce nanoparticles.