abstract the essential oil of cedrela odorata l. bark from s. tom'e and pr'incipe, where this plant is used in traditional medicine mainly for the treatment of malaria as well as a febrifuge and against diabetes, was investigated for the first time. the oil was obtained by hydrodistillation of the bark, and subsequently analyzed by gc, gc/ms and 13c-nmr. thirty-seven constituents were identified in the oil that was characterized by high and similar amounts of sesquiterpene hydrocarbons and oxygenated sesquiterpenes (43.9 and 42.4%, respectively). major compounds were -copaene (14.4%), -cadinol (11.2%), -eudesmol (9.4%) and -cadinene (9.2%). the oil from s. tom'e is different from those reported in samples of other origins in which -cadinol (11.2%) was not detected.