K10 was modified under aqueous and non-aqueous conditions using SbCl3 and the resultant catalysts were used for the Friedel-Crafts benzylation of benzene with benzyl chloride (BzCl) and benzyl alcohol (BzOH). Effect of activation temperature on the activity of the catalysts was also studied. The catalysts activated at 120 degreesC in both the cases were found to be more active. The outstanding observation of this investigation was the significant catalytic activity associated with Sb(III), particularly in view of the fact that SbCl3 is known to be the least active Lewis acid under homogeneous conditions.