Abstract The chemical composition of essential oil from leaves, stem bark, stem wood, root bark and root wood of two populations of Pilocarpus jaborandi and three populations of P. trachyllophus, collected in the Northeast of Brazil, were compared by GC/MS. 2-Tridecanone (48.7-92.6%) was the major component in all oils obtained from the stems and roots (21 samples). The oils obtained from the nine leaf samples, showed 2-tridecanone as the major component (25.2-60.7%) for four of them, whereas the others showed limonene (67.1%), spathulenol (32.8%), germacrene D (19.7%), (Z)-Î²-ocimene (24.4%) and Î±-cadinol (13.2%), respectively.