Blends of polycarbonate (PC)/poly(l-lactide) (PLLA) have great potential in applications ranging from packaging materials to consumer electronics. However, research into these blends is relatively limited compared with that into other polyesters. In this work, different contents of functionalized multiwalled carbon nanotubes (FMWCNTs) were introduced into PC/PLLA blends. The crystallization and melting behaviors of the nanocomposites were investigated using differential scanning calorimetry. The morphology of the nanocomposites and the dispersion states of the FMWCNTs were investigated using scanning electron microscopy, transmission electron microscopy and rheological measurements. The results showed that all samples were in the amorphous state during the injection-molding process. Although the co-continuous morphology features of samples was not changed, the presence of the FMWCNTs noticeably induced an increase of phase domains of PC, which was suggested to be the result of the formation of a percolated FMWCNT network structure. The electrical resistivity of the nanocomposites was greatly reduced when the content of FMWCNTs was increased to 2 wt%. The determination of mechanical properties showed that the addition of FMWCNTs facilitated an improvement of the fracture resistance. Another exciting aspect of this research was that the hydrolytic degradation ability of the blends was further improved by adding the FMWCNTs.