Essential oils, biosynthesized and accumulated in aromatic plants, have a wide range of applications in the pharmaceutical health, cosmetics, food and agricultural industry. This study aimed to analyze the secondary metabolites in some plant species in order to contribute to their chemotaxonomy. Leaves from Helicteres guazumifolia, Piper tuberculatum, Scoparia dulcis and Solanum subinerme were collected and their essential oils were obtained by means of hydro-distillation. The oil fraction was analyzed and identified by GC/MS. The extraction yields were of 0.004, 0.032, 0.016 and 0.005%, and the oil constituents of 88.00, 89.80, 87.50 and 89.47%, respectively. The principal oils found were: non-terpenoids volatile secondary metabolites (30.28%) in H. guazumifolia; sesquiterpenoids (20.82 and 26.09%) and oxigen derivated (52.19 and 25.18%) in P. tuberculatum and S. dulcis; and oxigen diterpenoids (39.67%) in S. subinerme. The diisobuthylphtalate (13.11%) in H. guazumifolia, (-)-spathulenol (11.37%) in P. tuberculatum and trans-phytol (8.29 and 36.00%) in S. dulcis and S. subinerme, were the principal constituents in their respective essential oils. The diisooctylphtalate were the essential oil common to all species, but the volatile compounds such as trans-pinane, L-linalool, beta-ionone, isophytol, neophytadiene, trans-phytol, dibutylphtalate and methyl hexadecanoate, were only detected in three of these essences. This suggests that these plants may require similar secondary metabolites for their ecological interactions, possibly due to common environmental factors.