Organized mesoporous alumina represents a very interesting molecular sieve exhibiting a narrow pore size distribution with higher surface areas compared to conventional aluminas, used as a support for catalytically active species in numerous large-scale industrial processes. This review encompasses various synthesis approaches to organized mesoporous aluminas, description of their structures and properties, and characterization by various experimental techniques. The potential of the mesoporous alumina with respect to use in catalysis is also outlined. Surface areas up to 800 m(2)/g and pore sizes ranging from 2.0 to more than 10 nm are characteristic for organized mesoporous aluminas prepared by neutral, anionic and cationic synthesis routes. Although utilization of mesoporous aluminas as a support in catalysis has not been reported frequently, they have a certain potential in hydrodesulfurization and metathesis reactions. (C) 2003 Elsevier B.V. All rights reserved.