abstract the chemical composition of essential oils isolated by hydrodistillation from ripe fruits and leaves of pourouma cecropiifolia martius, pourouma mollis tr'ecul and pourouma velutina martius ex miguel was determined by gc and gc/ms. from ripe fruits of p. cecropiifolici martius, 24 compounds were identified, accounting for 73.8% of the oil. oxygenated monoterpenes were found to be an important group of constituents with linalool (3.1%) predominating. a new monoterpene, 2-methox-1,7,7-trimethylbicyclo[2.2.1]hept-2-ene (2-methoxybornylene), was tentatively identified by mass spectrometry. in addition, 29, 37 and 26 constituents were identified in the leaf oils of p. cecropiifolia, p. mollis and p. velutina, respectively. aliphatic alcohols, aldehydes and esters (c3-c9) were quantitatively the most significant components. (z)-3-hexenol was clearly the dominant product occurring in contents of 26.7%, 22.3% and 3.2%, respectively. the major sesquiterpene hydrocarbons in the analyzed oils were -caryophyllene (9.1%) and (e,e)--farnesene (4.0%) from p. cecropiifolia oil; (e,e)-farnesene (1.7%) from p. mollis oil; and (1.5%) from p. velutina oil. linalool (26.1%) was the major compound identified in the volatile fraction of p. mollis. it was also identified in the oils of p. cecropiifolia (1.2%) and p. velutina (1.7%). phytol was the main constituent of the leaf oil of p. velutina. methyl salicylate was also identified in the leaf oils of p. cecropiifolia (1.6%), p. mollis (1.4%) and p. velutina (2.8%). key word index: pourouma cecropiifolia pourouma mollis pourouma velutina moraceaeessential oil composition2-methoxyhornylenehexadecanoic acid(z,z)-octadec-9,12-dienoic acid(z)-3-hexenollinaloolphytol