Cannabis has been used as a medicine for millennia. Current research has shown encouraging results for its use in the treatment of epilepsy. In cannabis, Δ9-tetrahydrocannabinol (THC) is the main psychoactive ingredient while cannabidiol (CBD) is the main non-psychoactive ingredient. THC has shown anticonvulsant properties in most animal models and many case reports. However, as yet, CBD does not have a completely understood mechanism of action. Numerous case reports, preclinical studies and clinical studies indicate that CBD and CBD-containing medications are able to help manage epilepsy in adults and children affected by refractory seizures, such as occur in Dravet syndrome and Lennox-Gastaut syndrome. Clinical trials are limited however. Although the data is promising, further preclinical and clinical studies are needed to better evaluate the potential therapeutic profile of CBD in epilepsy.