A supercritical anti-solvent (SAS) process was carried out to obtain micron and submicron particles (0.35-1.78 mu m) of silica from a solution with a silica precursor. The effects of different parameters such as pressure (120 and 150 bar), temperature (323 and 333 K), CO2 flow rate (20 and 35 g/min), liquid solution flow rate (4 and 8 mL/min) and nozzle diameter (0.1 and 0.2 mu m) on the outcome of the SAS process were analyzed. The TEOS: water molar ratio (1:4-1:17) was also evaluated and seems to play a major role in the precipitation of particles, especially in terms of agglomeration and morphology in that a higher amount of water leads to lower agglomeration of particles. Higher CO2 and lower liquid solution flow rates are recommended to obtain a smaller particle size with narrow particle size distribution (0.35 +/- 0.17 mu m). Lower temperatures are recommended to reduce the particle size. The rest of the assayed variables did not have a significant influence on particle size and size distribution. As far as the textural properties are concerned, silica particles with low porosity (1.41-10.22 m(2)/g) and certain hydrophilic character were generally produced.