The skeletal isomerization of 1-pentene at atmospheric pressure and 89 mm Hg 1-pentene partial pressure was investigated over SAPO-11, BEA and AIMCM-41 molecular sieves. The effect of the reaction temperature between 250 and 400 degrees C was studied. Acidity of the catalysts seems to play a more important role than the pore size in the reaction conditions used. (C) 2008 Elsevier B.V. All rights reserved.