Solid-state NMR spectroscopy is capable of determining the three-dimensional structures of peptides and proteins. A single crystal of N-acetyl-D,L-valine is used as a model of an immobile oriented peptide to illustrate the method. In this example, the 1H, 13C and 14N nuclear spin interactions present in natural abundance were used to determine the orientations of the peptide planes of the two molecules in the unit cell of the crystal lattice.