Fusobacterium nucleatum is a dangerous pathogen, and it has been linked to a variety of health problems, including cancer, periodontal disease, and pregnancy complications. F. nucleatum butanol dehydrogenase (FnYqdH) is a group of dehydrogenase enzymes that facilitate interconversion between butyraldehyde and butanol at the expenditure of a cofactor NAD (P)H. In this study, FnYqdH was successfully expressed and purified using Ni-NTA affinity, Q anionexchange, and gel-filtration chromatography. The protein crystal was obtained and diffracted to a resolution of 2.0 Å. The crystal belonged to the orthorhombic space group of I222, with unit-cell parameters of a = 64.77, b = 78.85, and c = 215.22 Å. The Matthews coefficient and solvent content were estimated to be 3.19 ų Da^–1 and 61.49%, respectively, assuming that the asymmetric unit contained only one recombinant protein molecule. Size-exclusion chromatography suggested that FnYqdH prefers to exist as a dimer in the solution.