Carbon dioxide (CO2) adsorption measurements were performed on MCM-41 silica samples prepared in the presence of cetyltrimethylammonium bromide (CTAB) at different temperatures from 333 to 393 K. Because of its relevance in practical applications, adsorption of dry CO2 was investigated at room temperature up to 45 bar using a magnetic suspension balance (MSB). The adsorption capacity at high pressure was found to increase with the increase of surface area as well as with pore ordering as reflected by the intensity of the (1 0 0) X-ray diffraction peak. The most promising MCM-41 sample in terms of CO2 adsorption capacity, i.e., MCM-41-100 prepared at 373 K, was compared to a number of typical CO2 adsorbents. At high pressure (e.g., 45 bar), MCM-41-100 exhibited higher volumetric capacity than activated carbons and 13X zeolite. Moreover adsorption of pure CO2 on MCM-41 at ambient temperature was completely reversible and exceedingly fast.