A fully bio-based blend with improved high temperature creep resistance containing Poly(lactic acid) (PLA) as the dominant component has been designed. The poor mechanical properties of the amorphous PLA above its glass transition have been corrected by blending it with Polyamide 11 (PA11), a semicrystalline bio-based polymer. The continuity of the latter heat resistant phase has been promoted through the addition of small amounts of organo-modified montmorillonite (OMMT). The selective positioning of the filler inside the PA11 and at the PLA-PA11 interface has been exploited to convert the drop-matrix morphology of a blend at 70 wt.% of PLA into a stable co-continuous one. This is mainly ascribed to the slowed relaxation dynamics of the host PA11 phase, resulting in a OMMT-rich PA11 framework that interpenetrates the major PLA phase and effectively contribute to bear stresses up to ~160°C, i.e. ~100°C above the PLA glass transition. Neither the mere reinforcing action of the filler nor changes in the crystallinity of the polymeric blend components are responsible for the observed improvement. On the other hand, a filler-induced clustering phenomenon concerning the PA11 domains may contribute in lowering the onset of continuity of the heat resistant phase. Looking for optimized formulations, we have found that lowering the PA11 content in the blend results in the loss of the high temperature creep resistance. On the other hand, increasing the OMMT content in the blend at 70 wt.% of PLA may bring about an excessive material embrittlement at room temperature.