In this work we investigate the influence of defects injected by ions of different mass and energy on the diffusion of B and Sb markers in bulk Si. MeV (Si or As) ions induce Sb transient enhanced diffusion, whose amount increases with increasing the near-surface vacancy supersaturation generated by the knock-on recoil mechanism. The enhancement effect lasts less than 2 h at 800 °C and less than 10 min at 900 °C. At higher (1000 °C) annealing temperature it appears that the influence of extra-interstitials introduced by the implants comes into play, inducing a retardation in Sb diffusion which is larger for the higher close implant. The effect of vacancy supersaturation observed in medium-energy implanted samples is considerably weaker than the one found in high-energy implanted ones. In the case of B marker high-energy implantation induces moderate enhanced diffusion, much smaller than the one observed -after medium-energy implants.