Herein, we report a strategy for top-down preparation of chitosan nanofibers and nanoparticles starting from chitin flakes as theprecursor material. These nanostructures were prepared through achitin nanofiber pathway as opposed to the previous work that uti-lizes chitosan flakes as the initial source. Further, we have usedultrasonication as the technique for mechanical disassembly. The objective of this work is to investigate the properties of chitosan nanofibers and nanoparticles prepared using above mentionedstrategy