We report a process for preparing microdot arrays of SiO2 from a tetraethoxysilane precursor containing either a cationic (CTAB) or non-ionic surfactant. Controlling the ink jet deposition parameters and precursor hydrolysis made it possible to obtain mesoporous silica with a Pm3n cubic structure, using CTAB, or an Fmmm orthorhombic structure, using a non-ionic surfactant. The addition of hydrophobic organosilane F3C(CF2)(5)CH2CH2Si(OC2H5)(3) leads to the most regular and best-defined three-dimensional microdot array with a constant diameter of 155 mu m and a regular space of 250 mu m.