L,L-lactide was polymerized in bulk at 120°C, 150 or 180°C by means of various metal oxides, carbonates or carboxylates. Yield, viscosities and optical rotation were measured and compared. Several catalysts enable a nearly complete conversion even at 120°C indicating rapid diffusion of the monomer in the solid reaction mixture. At 180°C only SnO and Sb2O3 proved to be useful catalyst, because they gave within 12 h yields > 80% along with an optical purity around 97%. Longer reaction times lead at 180°C to substantial racemization in all cases.