Wood degradation caused by fungi and insects is a major problem for the rubberwood industry. This study evaluated the potential of using pyrolysis liquids (wood vinegar) from Dyera costulata as a natural biocide against termites. The infestation rates of Coptotermes curvignathus on filter paper samples treated with 0.5%, 1.0%, 5.0% and 10.0% of Dyera costulata wood vinegar were observed in laboratory conditions. The effects of D. costulata wood vinegar treatment depended on the concentration. Filter paper samples treated with 10% D. costulata wood vinegar had the highest resistance against C. curvignathus attack, with the lowest relative mass loss, followed in rank order by the 5% and 1% treatments. Results from tests on Hevea brasiliensis wood treated with wood vinegar also showed a similar trend. The results suggest that D. costulata wood vinegar acts as a wood preservative against termites, provided proper concentration is used.