in the amazon region of brazil, the roots of different species of philodendron are used in the traditional medicine. philodendron fragrantissimum (hook.) g. don, locally known as 'cip'o-tracu'a', has very aromatic roots and is used for baths and fumigation. here, we describe the chemical composition of the essential oil from the roots of p. fragrantissimum obtained by hydrodistillation in a modified clevenger-type apparatus for 4 hours. the oil was analyzed by gas chromatography (gc) and gc/mass spectrometry (gc/ms). thirty-five substances were detected and the major components were -caryophyllene (29.9%), limonene (15.8%), -selinene (11.5%), -selinene (15.7%), -pinene (3.4%), -copaene (3.2%), -pinene (2.5%) and -cadinene (2.9%). to the best of our knowledge, this is the first report on the chemical composition of the essential oil from p. fragrantissimum. the high content of -caryophyllene was not observed in the other oils studied so far and might be considered a tool in taxonomy studies.