Introduction: Polylactic acid is an alternative to petrochemical polymers. Objective: To determine the optimal conditions for the synthesis of polylactic acid by direct polycondensation for the production of biomaterials. Materials and methods: 32 PLA studies were analyzed and 8 to specify their medical applications. Results: Start with commercial or fermented lactic acid between 25-50 mm Hg under vacuum, SnCl2/p-TsOH at 0.1-0.6% for 15-45 min with 100-300 W at 50-150°C. Conclusions: Several factors such as raw material, synthesis processes and pH influence the yield and type of polymer. PLA can be used as a biomaterial in different applications, especially in the health area.