Esterification of palmitic acid with methanol was studied on zirconia supported tungsten oxide solid acid catalysts prepared by both impregnation and co-precipitation methods; the tungsten loading and calcination temperature were varied. These catalysts were characterized by X-ray diffraction for structural elucidation and by temperature-programmed desorption of ammonia for their surface acidity. Whereas the impregnated catalysts exhibited both tetragonal and monoclinic phases of zirconia, at calcination temperatures beyond 500 degreesC their co-precipitated analogues showed stability towards the tetragonal phase. The formation of monoclinic phases of zirconia and crystalline tungsten oxide decreased the esterification activity, as a consequence of decreased surface acidity. Coexistence of tetragonal zirconia with the amorphous tungsten oxide offered maximum esterification activity. (C) 2004 Elsevier B.V. All rights reserved.