The diffusion of B and As in mechanically strnsed silicon has been investigated for initial implant doses of 1013, 1014, and 1015 cm-2, over a range of annealing temperatures. At stresses near the silicon yield point, no significant enhancement or retardation was observed. This was true even in plastically deformed samples with dislocation densities >1×107 cm-2. The results are consistent with the multiple charge state vacancy model of impurity diffusion in silicon. The B diffusivity appears to agree with the accepted activation energy of 3.59 eV and pre-exponential of 3.17 cm2/sec for intrinsic B diffusion.