Cancer is the second leading cause of death globally, and is responsible for an estimated 9.6 million deaths in 2018, following heart disease. It’s often treated with some combination of radiation therapy, surgery, chemotherapy and targeted therapy. The high cost, increasing drug resistance, and side effects of current therapeutic approaches are forcing the scientists to explore alternative medicines, the traditional medicine, as an option to find new chemical entities for treatment of cancer. Historically, natural products from plants were the source of virtually all medicinal preparations and have been exploited for treatment of several diseases and, more recently, they have continued to enter clinical trials or to provide leads for compounds that have entered clinical trials, particularly as anticancer agents. Essential oils are a complex mixture of natural, volatile, and aromatic compounds obtained from plant material. They possess different biological properties on humans, animals, and other plants. Since the middle ages, they have been widely used for bactericidal, virucidal, fungicidal, antiparasiticidal, insecticidal, medicinal and cosmetic applications, especially nowadays in pharmaceutical, sanitary, cosmetic, agricultural and food industries. Extensive documentation on the anticancer potential of essential oils and their constituents has been carried out several workers. The reported studies can be divided into in vivo and in vitro and are related to essential oils from wide variety of plants or, mainly, their constituents. In this review, we discuss the literature on the effects of essential oils in vitro and in vivo models of cancer, focusing on the studies performed with the whole oil rather than single constituents. Keywords: essential oils and chemical components, anticancer activity.