Eucalyptus globulus wood samples were submitted to fractionation with 95% acetic-acid solutions catalysed by small quantities of HCl. Experiments were performed at the normal boiling temperature using a liquor/wood ratio equal to 10 g/g. The effects of treatment time (0-180 min) and catalyst concentration (0-0.2%) on pulp yield, solid residue composition and cooking liquor composition were determined Pulp yields in the range 51.5-90.6% were obtained Extensive delignification of wood was achieved under a variety of operational conditions, leading to solid residues with less than 4% lignin. The lignin removal was modelled kinetically as the contribution of two parallel, first-order reactions. Pulps containing over 90% polysaccharides and glucan/polysaccharide ratios higher than 0.95 were obtained under selected conditions. Pentoses and furfural were identified as hemicellulose hydrolysis products. The kinetics of hemicellulose saccharification was modelled assuming two sequential, first-order, irreversible reactions. The maximum pentose recovery accounted for 37% of the potential amount. Under the conditions leading to optimum pentose recoveries, good delignification was achieved Furfural concentrations up to 4.3 g/l were obtained under the severest experimental conditions studied.