Protected glycosyl azides react with acyl chlorides in the presence of triphenylphosphine to afford glycosylamides in high yields, at room temperature. Starting from the β-glycosyl azides, the reaction is highly stereoselective and occurs with retention of configuration, whereas the α-azido anomers display a lower stereoselectivity giving rise to α/β mixtures of glycosylamides. The reaction was applied to several monosaccharidic azides and to lactosyl azide with various acyl chlorides; it was shown to be of general use for preparing 1,2-trans β-glycosylamides.