The effect of dislocations on the rate of diffusion of radioactive Ge71 in intrinsic germanium single crystals has been studied at temperatures near 740°C. The dislocations were introduced by either of two methods: (A) distorting the surface by lapping under pressure, thus producing a network of dislocations; (B) bending the specimens so as to introduce up to 2×106 parallel edge dislocations per cm2. Both deformation treatments produce an enhancement of self-diffusion relative to that in undeformed crystals. In both cases the diffusion can be described in terms of an enhanced volume diffusion with apparent diffusion coefficients up to 38% larger than the value for undeformed intrinsic specimens. © 1962 The American Physical Society.