The translational diffusion coefficients of supercooled heavy water ((H2O)-H-2) at atmospheric pressure were examined using pulsed-gradient spin-echo NMR diffusion measurements down to 244 K. At this temperature the diffusion coefficient was 1.67 x 10(-10) m(2) s(-1). The temperature dependence of the (H2O)-H-2 diffusion was distinctly non-Arrhenius. It was found that the temperature dependence of the diffusion could be modeled almost equally well by both Vogel-Tamman-Fulcher and fractional power law relationships. However, at the lowest temperatures the fractional power law equation appeared to be slightly better at describing the data.