The pressure dependence of the nuclear spin lattice relaxation time of the 63Cu nuclei in a powdered sample of cuprous oxide is reported at two temperatures for hydrostatic pressures in the range 1 to 5000 kg cm−2. It is shown that the experimental value of T1 at atmospheric pressure can be accounted for on the basis of an ionic point charge model for cuprous oxide. The variation of T1 with pressure is discussed on the basis of this model.