Bamboo, a lignocellulosic material, is a renewable source of interest as feedstock for production of cellulose derivatives by chemical functionalization. Optimization of hydroxypropylation of cellulosic material (average DP 816), isolated from bamboo (Dendrocalamus strictus) was, therefore, performed with respect to maximum percent hydroxylpropoxyl (% HP) contents under varying reaction conditions and studying their effect on the % HP. The optimized reaction conditions were aqueous NaOH concentration 22%, propylene oxide concentration 17.4 mol/AGU, temperature 50 C, duration of hydroxypropylation 4 h to yield hydroxypropyl cellulose of % HP 65.89. The eta(app) of 1 and 2% solutions of the optimized product showed it to be non-Newtonian pseudoplastic. (C) 2009 Wiley Periodicals, Inc. J Appl Polym Sci 113: 2450-2455, 2009