Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)In this study the volatile constituents from leaves and fruits of Julocroton triqueter (Lam.) Didr. (Euphorbiaceae), a medicinal plant from northwest Brazil, were investigated by GC/MS. Twenty one compounds, which represent about 96% of the total constituents of the essential oil, were identified. Caryophyllene oxide, humulene epoxide 11, trans-caryophyllene, occidentalol, alpha-humulene in the fruit and cis-carvyl acetate, spathulenol, cis-carveol, trans-caryophyllene, trans-carvyl acetate and alpha-humulene ill the leaves were the principal components. From one fraction of the hexane extract of the fruits a mixture of fatty acids were identified as: dodecanoic, tetradecanoic, hexadecanoic, 9-octadecenoic, cicosanoic, trieicosanoic and tetracosanoic acids. The partial analysis of the non-volatile constituents (hexanic fraction) from fruit allowed the isolation and characterization of tetracosan-1-ol (identify by (1)H and (13)C NMR, FTIR).5415557Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)