Silica nanospheres containing isoniazid (INH) was synthesized based on a modified Stober process. Synthesis parameters such as type of alcohol used as oil phase, tetra ethyl ortho silicate (TEOS) and ammonia (NH3) amounts, surfactant use and mixing time were altered and their effect on the release of INH was investigated. Results indicated lower amount of INH release when higher amount of TEOS was utilized in synthesis. Time of highest INH release was higher in the case of higher TEOS amount. NH3 had also a decreasing effect on INH release which had been due to the changes in pore structure. Scanning electron microscope (SEM) results clearly showed the necessity of surfactant use with smooth surfaces obtained with the samples where surfactant was utilized. Finally, mixing time was found to have a decreasing effect on the time of highest INH release and the amount of INH released from the spheres was also higher in the case of higher mixing time.