The mesoporous high surface area MCM-41 material was synthesized and used as a support material for the preparation of Co/MCM-41 samples. Co-2(CO)(8) was deposited from the gas phase onto the MCM-41 surface in a fluidized bed reactor. Pure MCM-41 and Co/MCM-41 samples were characterized by various spectroscopic and analytical methods. The MCM-41 mesoporous material showed considerable ability to adsorb Co-2(CO)(8) from the gas phase. The monolayer coverage after one direct deposition and decarbonylation cycle was ca. 20 wt % of cobalt. The metal loading increased up to 41 wt % using the pulse deposition method. The results of IR spectroscopy indicated that all silanols are accessible to the cobalt carbonyl. According to the N-2 adsorption/desorption studies, the surface area and pore size distribution were almost unaffected even in the case of high cobalt loadings. The samples were found to have a good metal dispersion.