Cannabinoids, psychoactive substances present in cannabis, have been known to mankind for hundreds of years. Apart from 9-tetrahydrocannabinol (THC) substances found in the cannabis herb with the highest toxicological value are cannabidiol (CBD) and cannabinol (CBN). The discovery of CB1 and CB2 receptors, located in various tissues (ranging from the brain to peripheral tissues), has defined the potential objective of these new chemical substances’ effects. Many studies on the application of cannabinoids in the treatment of various diseases such as diabetes, neoplasms, inflammatory diseases, neurological conditions, pain and vomitting were conducted. Drugs containing e.g. THC appear on the pharmaceutical market. Substances affecting cannabinoid receptors may show beneficial effects, but they may also cause the risk of side effects related mainly to the inhibition of central nervous system. The purpose of this dissertation is the analysis, whether the substances responsible for the effects of marijuana, can find application in medicine. Original articles and reviews were used to summarize the results of studies connected to the topic.