Biodegradable polymers are raising an increasing attention as a possible alternative to petroleum-based materials, since they can be produced from renewable resources at reasonable costs. Among all the promising biodegradable polymers, the most commonly studied is poly(lactic acid) (PLA). However, PLA has some processing limitations such as poor thermal and mechanical resistance and slow crystallization kinetics, if compared to other thermoplastic resins, which limits its complete access to industrial sectors. In this work, an attempt is made to overcome these limitations of PLA by using carbon-based materials, which have gained a new significant attention as a filler to enhance polymer properties. In particular, carbon black, and an ad-hoc functionalized carbon black were used. These carbon-based materials were melt compounded in a twin screw extruder and characterized by differential scanning calorimetry (DSC), rotational rheometry and GPC tests. PLA molecular weight, which is heavily reduced during melt extrusion of the neat polymer, can remain essentially unaltered by simple compounding with a minimum quantity of carbon black. Thermogravimetric analyses (TGA) indicate that the same carbon fillers, on the contrary, slightly destabilize PLA toward decomposition reactions leading to loss of volatile byproducts, which occur at temperatures higher than 300°C, i.e. far from melt processing conditions. Experimental results show that the compounds exhibit a faster crystallization kinetics if compared to the neat resin, and a good thermo-mechanical stability. In particular the functionalized carbon black compound shows the fastest crystallization kinetics, probably due to a specific nucleation effect of the functional tails. Furthermore, solid films made of these carbon based composites, exhibit a slower hydrolysis in water.