Ring Opening Polymerization of rac-lactide and ε-caprolactone as well as their copolymerization was achieved by means of bismuth tris-silylamide in solution and at temperatures below 75 °C. The best performances in terms of control of the polymerization were obtained in presence of an alcohol as chain transfer agent. A PLA-based copolymer containing up to 23% ε-caprolactone can be prepared. When activated with a borane molecule, bismuth tris-silylamide produces polymers having narrower polymer distributions.