The purpose of this study was to investigate how the properties of poly(lactic acid) (PLA) can be improved using nanoclay and thermoplastic polyurethane (TPU) as additives. PLA was extrusion compounded with nanoclay using a filler content of 1 to 8 wt % and a TPU content of 3 to 20 wt %. Talc was also added as a nucleating agent and the effect of talc on the crystallization was characterized using DSC. It was found that it resulted in a decrease in crystallization temperature upon heating, although the degree of crystallinity appeared to be nearly unaffected. A positive effect of nanoclay on the crystallization could not be detected. Mechanical testing showed an increase in flexural and tensile modulus of more than 40 % when the clay content increased from 0 to 8 wt %. The flexural and tensile strength reached a maximum at a clay content of 2 wt %. The addition of TPU resulted in an improvement of the impact strength by 65 % for a TPU content of 20 wt %. Also the heat distortion temperature (HDT) was investigated, but it was found that the addition of clay did not have a large effect on the HDT.