Copolymers of 1,1-lactide with epsilon-caprolactone have been investigated in order to develop valuable biodegradable materials for medical applications. The syntheses of homopolymers and copolymers of 1,1-lactide and epsilon-caprolactone by ring-opening bulk polymerization were performed using stannous octoate as initiator at 120 degreesC. The compositions of the copolymers were systematically varied by polymerization of monomer mixtures containing from 10 to 90 95 of epsilon-caprolactone, at 10% step of variation. High polymerization conversions were observed for homopolymers and copolymers syntheses. Synthesized products were characterized by gel permeation chromatography (GPC) and nuclear magnetic resonance spectrometry (NMR). The analyses of the segment lengths by C-13-NMR spectroscopy indicated the predominance of random copolymers formation and the transesterification reaction was not detected.