AbstractXylo-oligosaccharides were obtained from Miscanthus x giganteus. The process was designed as a biorefinery scheme, which seeks the separation of the three main components: cellulose, hemicelluloses, and lignin. To extract the hemicelluloses, particularly xylans, in an efficient way, Miscanthus was subjected to autohydrolysis. The system was evaluated for the effects of temperature (160 to 200oC) and reaction time (15 to 60 min) on various parameters, reflecting the changes undergone during the process. The results showed that autohydrolysis is a suitable method for obtaining high yields of xylo-oligosaccharides, reaching values close to 65% of the dissolved xylans (based on the initial amount of potential xylose). Analysis of the process by using the severity factor (RO) allowed for the identification of a set of time-temperature values for which the fractionation was optimal.