A mild, efficient and expeditious method has been developed for the chemoselective conversion of aldehydes to the corresponding acylals in excellent yields, using acetic anhydride in the presence of catalytic amount (0.01-0.1 mol%) of In(OTf)(3). Ketones remain unaffected under the reaction condition. In(OTf)(3) can be recovered and reused without any loss of its catalytic activity. (C) 2004 Elsevier B.V. All rights reserved.