Dispersion curves for the [00ζ] (∆), [ζζ0] (Σ), [ζζζ] (Λ), and [1212ζ] (T) directions in ND4Cl were measured at 85 °K by inelastic scattering of slow neutrons using the McMaster triple-axis crystal spectrometer at Chalk River. The single crystals were grown from solution. A torsional (librational) branch, flat within about 2%, with an average frequency of 8.3 × 1012 cps, was found. Results are compared with a modified rigid-ion-model calculation based on Parlinski's formulation. Symmetry points and branches in the dispersion curves are classified according to their symmetry species. The Lyddane-Sachs-Teller relation as generalized by Cochran holds within experimental accuracy.