Carbon-13 spin-lattice relaxation parameters of solid Delrin were measured by means of high-resoln. solid-state carbon-13 NMR. Carbon-13 spectra and relaxation parameters clearly show two different types of carbon-13 nuclei, which are assigned to amorphous and cryst. region, in accord with the accepted 2-phase model of semicryst. poly(oxymethylene). The data indicated that mol. motions do take place in the cryst. regions as well as in the amorphous regions and that the motions in these two regions differ in their amplitudes rather than in their correlation frequencies.