Foamed polymers are used in many fields as insulation and packaging. Due to environmental constraints, biopolymer foams are becoming a viable alternative to petrochemical plastics while keeping the properties without drawbacks. In this study, a biobased and biodegradable polymer, poly-(lactic acid) (PLA) was foamed with a green process based on hot-melt extrusion combined with supercritical CO2. Furthermore, starch and thermoplastic starch (TPS) were used and blended with PLA. Different operating parameters (additive content, temperature, and CO2 mass fraction) were studied. Finally, foams with a porosity over 95% were obtained. By varying the operating parameters, we were able to observe manufacture foams different morphologies. Blending with additives as starch allows to overcome the low melt strength and slow crystallization of PLA. Both PLA and additives are biodegradable after exposure to moisture and they can substitute petroleum synthetics polymers.