AbstractsCurrently, much effort is being placed into obtaining extracts and/or essential oils fromCannabis sativaL. for specific therapeutic purposes or pharmacological compositions. These potential applications depend mainly on the phytochemical composition of the oils, which in turn are determined by the type ofC. sativa and the extraction method used to obtain the oils. In this work, we have evaluated the contents of secondary metabolites, delta-9-tetrahydrocannabinol (THC), and cannabidiol (CBD), in addition to the total phenolic, flavonoids, and anthraquinone content in oils obtained using solid–liquid extraction (SLE) and supercritical fluid extraction (SCF). Different varieties ofC. sativawere chosen by using the ratio of THC to CBD concentrations. Additionally, antioxidant, antifungal and anticancer activities on different cancer cell lines were evaluated in vitro. The results indicate that oils extracted by SLE, with high contents of CBD, flavonoids, and phenolic compounds, exhibit a high antioxidant capacity and induce a high decrease in the cell viability of the tested breast cancer cell line (MCF-7). The observed biological activities are attributed to the entourage effect, in which CBD, phenols and flavonoids play a key role. Therefore, it is concluded that the right selection ofC. sativavariety and the solvent for SLE extraction method could be used to obtain the optimal oil composition to develop a natural anticancer agent.