Cannabinoids are the major active components of the most widely used illegal drug – marihuana. They have a long history of the medicinal use. However, they are still a controversial topic in oncological praxis. Cannabinoids play a role in different organs of human body and they are an integral part of the newly described endocannabinoid system, which regulates several body functions. The important function of endocannabinoids which is related to cancer, is the regulation of cell cycle and cell survival pathways. Presented review gives three different views on the association between cannabinoids and cancer. First, the treatment of adverse symptoms of oncological therapy – nausea and vomiting inhibition, appetite stimulation, pain relieving, mood modulation and muscle stiffness relieving. Second, in the late 1990s, three possible mechanisms of antitumour action were identified – apoptosis induction, direct cell cycle arrest and angiogenesis and metastasis inhibition. The phase I/II of clinical trials are carrying out in Spain. They study effects of local administration of tetrahydrokanabinol on the growth of glioblastoma multiforme. Third, the results of the newest study focused on the association between cannabinoids use and cancer risk showed no significant association between increased cancer incidence and cannabinoids use and it does not depend on the amount of used cannabis. It is important to establish the association between marihuana use and cancer risk regarding the consideration of advantages and risks of medicinal cannabinoids use and the impact on public health.

        Key words: cannabinoids, endocannabinoid system, palliative therapy, tumor growth regulation, cancer risk.