The effects of a partial hydrolysis treatment on the surface energies of three southern hardwood species, red oak, sweetgum, and yellow-poplar were examined. Miniature beams machined to 3x15x150mm (txrxl) were water-saturated and subjected to a partial hydrolysis at 150 degrees C for 30min in 1% sulfuric acid, water, or 1% sodium hydroxide solutions. Untreated wood beams were used as controls. Dynamic contact angle specimens were planed from the beams to a thickness of 0.25mm and cut to a length of 15mm for analysis via the Wilhelmy plate technique. Surface energies for the wood/treatment combinations were calculated using the geometric mean procedure. Results indicated that acid and water treatments improved the wettability for all species. Alkaline treatment effects were species-specific. All treatments improved the surface energy of red oak. The dispersive forces accounted for the majority of the surface energies.