Sugarcane bagasse based cellulose nanocrystals (CNCs) and poly (vinyl alcohol) (PVA) were used to fabricate biodegradable porous foam bionanocomposites for application in biomedical applications by thermally- induced phase separation (TIPS) (freeze drying) technique. Aqueous suspension of cellulose nanocrystals and poly (vinyl alcohol) (PVA) solution in water were mixed to prepare (20/80) (v/v) composition of these polymers. For the comparative study 3D porous PVA foam was also prepared. Samples were characterized by FE-SEM, FTIR, X-ray diffraction analysis, porosity and pore size by ImageJ software. FE-SEM showed the surface morphology of pores distribution of the foam samples. The porosity of 3D porous PVA foam and 3D porous CNCs/PVA bionanocomposite was calculated as 90.8% and 89.0% respectively. The functional groups and crystallinity of the samples were determined by FTIR and X-ray diffraction spectra, respectively. The diameter of CNCs was in the range from 29 nm to 65 nm and the average diameter was calculated as 43± 3 nm by image analysis using ImageJ software. Thus produced porous composite in the present study might find potential applications to be used in biomedical applications.