Via a batch process in an autoclave, the foam processing of neat polylactide (PLA) and two different types of PLA/layered silicate nanocomposites has been conducted using supercritical carbon dioxide as a foaming agent. The morphological correlation between the dispersed silicate particles with nanometer dimensions in the bulk and the obtained closed-cell structure of the foam is discussed. This is the first report that deals with the possibility of preparing biodegradable nanocellular polymeric foams via nanocomposite technology.