It was shown that 3-amino-3-deoxy-D-glucose, one of the constituents of the kanamycin molecule and a metabolite of Bacillus sp., inhibits the bacterial synthesis of cell wall. The antibiotic (100 microgram/ml) significantly inhibits the growth of Staphylococcus aureus FDA 209P as well as the incorporation of DL-[14C]alanine into the acid-insoluble macromolecular fraction of its growing cells in the presence of chloramphenicol (100 microgram/ml). In contrast, the antibiotic does not affect the incorporation of [3H]thymidine, [3H]uridine and L-[14C]leucine. The other constituents of kanamycin, 6-amino-6-deoxy-D-glucose and deoxystreptamine do not inhibit the synthesis of bacterial cell wall peptidoglycan.