Chitin nanofibers were prepared from prawn shell by a simple grinding treatment after the removal of proteins and minerals. Since the exoskeleton of prawn is made up of a finer structure than crab shell, nano-fibrillation of prawn shell was easier than that of crab shell, which allow chitin nanofibers to be prepared under neutral pH conditions. The prepared chitin nanofibers were highly uniform and the width was 10-20 nm, which was similar to nanofibers from crab shell treated under acidic conditions. The preparation method for chitin nanofibers from prawn shells without an acidic chemical was applicable to many prawn species. (C) 2010 Elsevier Ltd. All rights reserved.