The leaf oil ofBrucea jawanica(L.) Merr. has been investigated to afford two monoterpene hydrocarbons (4.10%), seven oxygenated monoterpenes (27.16%), four ses-quiterpene hydrocarbons (6.25%), three oxygenated sesquiterpenes (3.13%) and four phenyl derivatives (48.45%). One of these oxygenated monoterpenes, 1-hydroxy p-menth-4 (8) enolide [1] has been isolated and its structure was elucidated by spectroscopic methods. The major constituents of the oil are dillapiole (22.5%), thymol (17.2%) and a-thujone (8.4%).