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. Theobjective of this work is to investigate the properties of chitosannanofibers and nanoparticles prepared using above mentionedstrategy