We demonstrate that β- N -acetyl- d -glucosaminyl-(1,4)- d -glucosamine (GlcNAc-GlcN) enhances the chitin-metabolizing ability of V. parahaemolyticus . Members of the genus Vibrio are chitin-degrading bacteria, and some species of this genus are associated with diseases affecting fish and animals, including humans (F. L. Thompson, T. Iida, and J. Swings, Microbiol Mol Biol Rev 68:403–431, 2004; M. Y. Ina-Salwany, N. Al-Saari, A. Mohamad, F.-A. Mursidi, et al., J Aquat Anim Health 31:3–22, 2019). Studies on Vibrio are considered important, as they may facilitate the development of solutions related to health, food, and aquaculture problems attributed to this genus. This report enhances the current understanding of chitin degradation by Vibrio bacteria.