4-Deoxy-4-fluoro-β-D-glucopyranose, C(6)H(11)FO(5), (I), crystallizes from water at room temperature in a slightly distorted (4)C(1) chair conformation. The observed chair distortion differs from that observed in β-D-glucopyranose [Kouwijzer, van Eijck, Kooijman & Kroon (1995). Acta Cryst. B51, 209-220], (II), with the former skewed toward a B(C3,O5) (boat) conformer and the latter toward an (O5)TB(C2) (twist-boat) conformer, based on Cremer-Pople analysis. The exocyclic hydroxymethyl group conformations in (I) and (II) are similar; in both cases, the O-C-C-O torsion angle is ∼-60° (gg conformer). Intermolecular hydrogen bonding in the crystal structures of (I) and (II) is conserved in that identical patterns of donors and acceptors are observed for the exocyclic substituents and the ring O atom of each monosaccharide. Inspection of the crystal packing structures of (I) and (II) reveals an essentially identical packing configuration.