The synthesis of mesoporous MCM-41 silica at low temperature under basic conditions using cetyltrimethylammonium bromide (CTAB) is reported. MSM-41 samples were prepared with different synthesis temperature and under hydrothermal operation. Samples were characterized by low angle X-ray diffraction, SEM and TEM analyses. It is shown that synthesis temperature and hydrothermal operation affected the SiO2 yield, morphology and particle size of the MCM-41 samples.