We report a H-1-H-2 dipolar NMR study of the water molecule in magnetically H-1 dilute crystalline hydrates. From the spectra obtained at two different magnetic fields,H-1 chemical shift (CS) tensors were directly determined. A clear correlation was observed between the H-1 CS tensor of hydrogen-bonded water molecules and hydrogen bond environment. Specifically, the H-1 chemical shieldings along directions parallel and perpendicular to the H ... O hydrogen bond were found to change in opposite directions with respect to hydrogen bond length. The parallel component of the H-1 CS tensor becomes more shielded as the hydrogen bond length decreases, whereas the perpendicular component becomes less shielded. This fact makes the span of the H-1 CS tensor four times, more sensitive to the hydrogen bond length than the isotropic H-1 chemical shift. Although it has been commonly assumed that the H-1 CS tensors in O-H ... O hydrogen-bonded systems are axially symmetric, this is not the case in this study. The asymmetry parameter of the H-1 CS tensor was found to depend on the hydrogen bond angle, angle O-w-H ... O, in crystalline hydrates.