Esterification of phenylacetic acid with phenol, cresols, nitrophenols and resorcinol has been carried out in the presence of montmorillonite clay exchanged with HI-ions, Al3+-ions and polyhydroxy oligomer cations of Al. Na+-montmorillonite (raw clay) was inactive, H+- and Al3+-montmorillonites, dried at 100degreesC, showed 52 and 67% conversions to ester, respectively, upon refluxing the phenylacetic acid (20 mmol) and p-cresol (40 mmol) for 6 h. While Al3+-montmorillonite dried at 200degreesC showed a conversion of 36% the same catalyst when dried at 400degreesC showed no conversion. Montmorillonite exchanged with aluminium polyhydroxy oligomers dried at 100degreesC and calcined at 500degreesC to get pillared clay (d001 = 17.5 Angstrom) failed to bring about the esterification. Effect of concentration of reactants, amount of catalyst and the reaction time on the yield of p-cresyl phenylacetate has been investigated. The esterification of phenylacetic acid with phenol and substituted phenols like m-cresol, o-cresol, p-nitro phenol and o-nitro phenol showed reduced yield due to steric factors. The activity of the clay catalyst after regeneration has also been studied. (C) 2004 Published by Elsevier B.V.