Self-diffusion in gold single crystals has been studied at temperatures between 335 to 390 °C for times between 15 and 30 min. The concentration profiles, obtained by use of a sensitive sectioning technique, consist of a region that appears to be characteristic of bulk diffusion, followed by a deeply penetrating 'tail' that is structure sensitive. Diffusion coefficients extracted from the initial portion of the curves are somewhat larger than those predicted from an extrapolation of high temperature measurements. The results are interpreted in terms of a combination of normal lattice diffusion and fast diffusion along dislocations.