The production of ethanol using Eucalyptus dunnii bark pretreated with 1-butyl-3-methylimidazolium chloride ([BMIM] Cl) as ionic liquid (IL) was studied. In the present work high ethanol yields were obtained using the minimal quantity of IL necessary for wetting but not dissolving the lignocellulosic material. The best result obtained was 70% of ethanol yield using an IL: bark ratio of 5: 1, with separate hydrolysis and fermentation (SHF) process, and a cellulase load of 50 FPU/gram of pretreated material. (C) 2016 Elsevier Ltd. All rights reserved.