Hyptis suaveolens (L.) Poit. belongs to the Lamiaceae family and is widely used in folk medicine in various countries. Th e essential oils from H. suaveolens have been extensively investigated and are mainly composed of monoterpenes and sesquiterpenes, although significant diterpene content has been reported in recent studies. The survey of the literature concerning H. suaveolens essential oils revealed a high level of chemical variability in terms of quantity and composition that is commonly observed for volatile oils from other plant species. However, few researchers have dealt with the reasons for such chemical variability. Our research group has been investigating the relationships between growing conditions of the plants and the H. suaveolens (L.) Poit. essential oil composition. The results of these investigations have led to some advances in the characterization and knowledge of H. suaveolens chemotypes from Brazil. Nevertheless, since this species presents high level of genetic polymorphism and allows it to adapt to the alterations in environmental features resulting in interpopulational and intrapopulational variability in the volatile oil chemical compositions. Consequently, biochemical assays on the biosynthetic pathway are required in order to detect the molecular mechanisms involved in inducing differential terpenoid biosynthesis within H. suaveolens. These are some of the challenges which require resolution leading to an understanding of the complex secondary metabolism of this species, thereby making possible the volatile oil chemical standardization seeking productivity and phytotherapy.