Bandarhola (Duabanga sonneratioides) heartwood was treated with 40 : 60 creosote petroleum oil mixture by the Lowry empty cell process using different schedules and the effects of varying pressure, treating time and final vacuum period on penetration and absorption were studied. This species, inspite of presence of tyloses in the vessels, was highly permeable to the preservative mostly along the grain. Transverse penetration from the surface was, however, low. The reason for higher permeability along the grain is attributed to the presence of numerous intervessel pits with perforated pit membranes. Increasing pressure and treating time increased penetration and absorption. At 82°C preservative temperature, saturation in absorption was reached in about 120 minutes. Final vacuum recovered about 25 per cent of the absorbed preservative, leaving the rest in the wood as net retention.