Contamination of medicinal plants with heavy metals as Pb and Cd can affect the growth and the essential oil production of the plants and represent a risk to those who consume as medicine. This study aimed to evaluate the effects of absorption and localization of Pb and Cd on growth, ultrastructural aspects of leaves and essential oil yield and composition of Mentha arvensis,applied on the soil with increasing concentrations (8, 16, 32, 64 and 128mg kg -1 (8, 16, 32, 64 and 128mg kg -1