Polylactic acid (PLA) is considered as a biodegradable, thermoplastic, and environmentally benign green polymeric material. It has wide applications in biomedical field due to its characteristic features. However, its application is often restricted for particular biomedical applications due to its brittleness, mechanical strength, conductivity, and processibility. These properties can be overcome by the reinforcement of small amount of carbon nanotubes (CNTs) in PLA matrix. In the present chapter, we will discuss briefly about PLA, PLA nanocomposites, CNTs, PLA/CNTs nanocomposites, and their biomedical applications.