In the search for renewable energy sources, elephant grass is an alternative substrate for ethanol production, but this substrate must be hydrolyzed by cellulases and xylanases to liberate fermentable sugars. During enzymatic hydrolysis, cellulase activity is reduced by the irreversible adsorption of cellulase onto cellulose, decreasing the rate of hydrolysis. Adding surfactants during hydrolysis can improve the process. The effects of Tween (R) and Triton (R) surfactants on the enzymatic hydrolysis of elephant grass were evaluated in this context. The data indicate that pretreatment with sodium hydroxide, along with a smaller particle size (0.075-0.152 mm) and the use of Tween 80 (R), increased the efficiency of releasing reducing sugars from pretreated elephant grass biomass. Thus, it is possible to reduce grinding costs in second-generation ethanol production through the use of surfactants, as they allow efficient hydrolysis of larger biomass particles. (C) 2014 Elsevier Ltd. All rights reserved.