From leaves of Guarea kunthiana one new kaurene diterpene (ent-kaur-16-en-2-one) was isolated along with eight known diterpenes (ent-kaur-16-ene, ent-3alpha- and 3beta-hydroxykaur-16-ene, kolavelool, kolavenol, kolavenal, ent-13-epi-manoyloxide and (-)-nephthenol), four sesquiterpenes (alismol, alismoxide, spathulenol and 4beta,10alpha-aromadendranediol), polyprenol-12 and alpha- and delta-tocopherols. Kolavenal is reported for the first time as a natural product, as well as the occurrence of cembrane- and ent-kaurane-type diterpenes in the Meliaceae.