We report on photoluminescence in the 1.3 and 1.7 μm spectral ranges in silicon doped with dysprosium. This is attributed to the Dy3+ internal transitions between the second Dy3+ excited state and the ground state, and between the third Dy3+ excited state and the ground state. Luminescence is achieved by Dy implantation into Si substrates codoped with boron, to form dislocation loops, and show a strong dependence on fabrication process. The spectra consist of several sharp lines with the strongest emission at 1736 nm, observed up to 200 K. No Dy3+ luminescence is observed in samples without B codoping, showing the paramount importance of dislocation loops to enable the Dy emission.