The catalytic properties of the Cr3+- and Fe3+-loaded clinoptilolites were screened in the liquid-phase isomerization of alpha-pinene and the major products were found to be camphene and limonene. Selectivity to camphene was superior for the 0.7Fe-CL catalyst than those observed for the Raw-CL and 0.4Cr-CL catalyst. Over raw clinoptilolite, the proportion of limonene and other isomers reached similar to 65% while it was similar to 15% with 0.7Fe-CL and similar to 56% with 0.4Cr-CL. The results also show that the selectivity to camphene increases with increasing reaction time reaching up to about similar to 72% at 428 K over 0.7Fe-CL catalyst. (C) 2012 The Korean Society of Industrial and Engineering Chemistry. Published by Elsevier B.V. All rights reserved.