The use of the exogalactanase from Aspergillus niger var. aculeatus was tested for the enzymatic synthesis of galactosyl-derivatives from galactan and various accepters such as aliphatic alcohols (methanol, ethanol, 1-propanol, 2-propanol, and butanol), hydroxylic aminoacids (serine, threonine), cysteine, and N-acetylglucosamine. Enzymic reaction with every acceptor bearing a primary hydroxylic group led to the appearance of a new peak in high performance liquid chromatography analysis. This peak eluted as N-acetyllactosamine when N-acetylglucosamine was used as acceptor and it was identified by C-13 nuclear magnetic resonance spectroscopy as 1-O-ethyl-beta-D-galactopyranoside and 1-O-(L-serine)-beta-D-galactopyranoside, with ethanol and serine as acceptor. This study demonstrated that the exogalactanase from Aspergillus niger var. aculeatus catalyzed the transfer of a galactosyl residue onto the primary hydroxyl group of accepters and can be used to synthesize some molecules of chemical or biological interest.