In the present work non-supported microfiltration ceramic membranes have been made from different aluminosilicate paste formulations. The cast green dopes were sintered at temperatures between 1100 and 1400degreesC. The membrane characterisation was made by scanning electron microscopy (SEM), mercury porosimetry, gas and water permeabilities and microorganisms rejection. The results indicate that an appropriate election of the size of the particles in the paste and of the final sintering temperature allows to obtain membranes with different mechanical and structural properties, with mean pore sizes within the range from 0.1 to 1 mum, that make them suitable for microfiltration. (C) 2004 Elsevier B.V. All rights reserved.