Cellulose is a naturally abundant organic polymer used by many researchers to establish various biomedical applications due to its biocompatibility, biodegradability, low toxicity, excellent physical, chemical, and mechanical properties. Lately, excellent mechanical properties of nanocellulose have made it one of the most promising nano-bio materials. This chapter reviews the source and structure of nanocellulose in the form of cellulose nanocrystal and cellulose nanofibrils, and the enhancement of the production process in order to explore its applicability in various technical fields. Finally, we also discuss and review the future aspects of cellulose nanomaterials or nanocellulose in biomedical engineering applications. © 2021 Elsevier Inc.