We report experimentally measured cross sections for pressure broadening of ammonia inversion transitions by J=0, ortho-D-2 at temperatures of 18-40 K. These measurements were made in a quasiequilibrium cell using the collisional cooling technique. Cross sections for broadening of the metastable (J,K)=(1, 1), (2, 2) and (3, 3) inversion transitions ranged from 67.5 Angstrom(2) for (1, 1) at 20.0 K to 100.1 Angstrom(2) for (3, 3) at 25.0 K. The J=0, ortho-D-2 cross sections were found to be consistently larger than previously measured cross sections for low temperature broadening of NH3 by both He and H-2. (C) 2004 American Institute of Physics.