The applications of polylactic acid (PLA) have been increasing over the past decades due to increased commercial production and its properties. Good biocompatibility, biodegradability and mechanical properties have made this polymer a great candidate for use as the matrix of porous composite scaffolds used for bone regeneration purposes. In this study, porous PLA monoliths are fabricated via nonsolvent-induced phase separation. First the PLA-dichloromethane (solvent)-hexane (nonsolvent) ternary phase diagram is developed at room conditions in order to identify the liquid-liquid phase separation region of this system. Subsequently, some compositions are selected from this region, foams are created, and characterized in terms of crystallinity and pore architecture. The results show that this foaming technique has great potential to meet the required criteria for manufacturing of highly porous scaffolds.