This experiment addresses the effect of aluminium oxide nano powder in hybrid combinations of sisal/coir, sisal/banana and banana/coir. The alumina nano powder is green synthesized from the leaf of ‘Muntingia Calabura’ using 4:1 ratio of leaf extract and aluminum nitrate solution. Synthesized nano powder is used for upgrading mechanical, thermal and vibration damping applications of hybrid natural composites. Sisal/coir hybrid composites enhanced tensile, flexural and impact properties by 30.86%, 13.34% and 16.49% with addition of nano filler up to 3%. Sisal/banana hybrid composites add to the tensile, flexural and impact properties by 35.64%, 12.20% and 8.24%. Similarly banana/coir composites also showed the same path. DSC results revealed improvement in endothermic peak, initial temperature and endothermic enthalpy by nano substitution. Sisal/banana/coir combinations enhanced the natural frequency and damping values by nano filler in first three modes of vibration. In the same fiber percentage of 35 with varying nano powder content sisal/banana and sisal/coir has higher damping values than banana/coir due to smaller diameter of sisal (100–200 μm) than banana and coir. SEM images proved improvement in introducing nano powder into the natural composites, showing more of even distribution with reduced void content.