Hydroxymethylation of anisole has been carried out over SnO2-CeO2 catalysts in the temperature range 623-723 K. Methoxybenzaldehyde (anisaldehyde) and condensation products were formed along with minor quantities of methoxybenzyl alcohol, o-cresol, phenol and 2,6-xylenol. A maximum anisaldehyde selectivity of 64% was obtained at 623 K at an anisole conversion of 46% under optimized conditions. Catalytic activity of these systems in the formation of aldehyde is ascribed to the presence of weak acid sites and redox metal sites.