The fabrication of asymmetric alumina ultrafiltration membranes using acetic acid surface stabilized alumina nanoparticles (A-alumoxanes) has been investigated. Contacting alpha -alumina supports with an aqueous solution of A-alumoxane (after firing to 1000 degreesC) yields a defect free alumina membrane with a thickness of ca. 2 mum. The alumoxane-derived membranes have a molecular weight cut-off in the range of 35,000-44,000 g mol(-1), high porosity, and a permeability that is comparable to or greater than that of commercially available alumina membranes. SEM and AFM show that the surface of the alumoxane-derived membranes is quite smooth and contact angles show that the membrane is hydrophillic. A comparison with commercial alumina and polymer membranes, as well as those derived from sol-gel methods is presented.