The steaming process, applied to logs before chipping, affected positively the dimensional stability of eucalyptus particleboard whereas, the internal bonding. The modulus of rupture (MOR) and internal bond strength (IB) values of the panels produced from steamed log parts without hardener were found to be higher than those of the panels produced by adding hardener into the urea formaldehyde (UF) glue. The steaming process did not have a clear effect on the IB of the panels bonded with melamine-urea formaldehyde (MUF) resin. The IB values of the panels bonded with MUF resin were higher than those of the panels bonded with UF resin. The MOR values of the MUF-bonded panels were higher than the requirement for general purpose panels. The steaming process caused an extra improvement in the thickness swelling (TS) of the panels bonded with MUF resin, which has higher resistance to water and weather than UF resin. The TS of the panels produced without hardener was half of the value obtained for the panels bonded with hardener-added UF resin. (c) 2005 Elsevier Ltd. All rights reserved.