Autocatalytic hydrothermal process conditions were used to study Ulex europæus (Gorse) as a source of xylan compounds. The aim was to study the possibilities for using this unutilised biomass material to produce xylans. Ulex is an evergreen shrub that grows in the northwest of Spain and has no economic value. Therefore, Ulex is considered a promising candidate as a biomass source. Ulex showed a total xylose content of 12%, thus qualifying it as a suitable material to extract xylan-derived compounds. Autohydrolysis was applied to extract xylans from Ulex. To find the best conditions for xylan extraction, samples of Ulex were subjected to different temperatures and time conditions. Results indicate that autohydrolysis is a suitable method to selectively extract xylans at temperatures between 160 and 190 °C for 5–30 min, reaching a maximum xylan recovery of almost 63% of the initial xylan at 180 °C for 30 min, with only small effects on cellulose and lignin contents.