Carbon molecular sieves (CMS) have been prepared from locally available palm shell of Tenera type by a thermal treatment technique involving carbonization followed by steam activation and benzene deposition technique. Carbonization of the dried palm shells was done at 900 degrees C for duration of 1 h followed by steam activation at 830 degrees C for 30-420 min to achieve activated carbons with different degree of burn-offs. The highest micropore volume of activated carbon obtained at 53.2% burn-off was found suitable to be used as a precursor for CMS production. Subsequent benzene deposition onto activated samples at temperature range from 600 to 900 degrees C for various benzene concentrations have resulted in a series of CNIS with different kinetic selectivities. The molecular sieving behaviour of the CNIS products was assessed by kinetic adsorption isotherms of O-2, N-2, CO2 and CH4 at room temperature. (c) 2007 Elsevier B.V. All rights reserved.