In order to remove the lignin residues, two consecutive bleaching steps using NaClO2 were applied. After bleaching, lignin and hemicelluloses were completely removed from fibers. The bleached garlic straw (BGS) resulting in almost pure cellulose fibres, which reached 86% wt. In this sense, the applied purification process was effective and the composition of BGS became suitable for the extraction of nanocellulose.