Propolis is a traditional nutritional supplement produced by bees and widely used as a folk remedy around the world. Its chemical composition and biological activities varies depending on the geographical location, botanical origin, season and the type of bees. In Brazil, the most popular and the most researched grade is "green" propolis, largely produced in the State of Minas Gerais, from the plant Baccharis dracunculifolia. This specific grade of propolis when properly processed shows remarkable activities as an antitumoral (cytotoxic, anti-proliferative and antimetastasic), analgesic and anti-inflammatory, immune-modulator, antioxidant, antimicrobial and healing agent. It has been safely used either by doctors or as a folk remedy in Brazil, Japan and many other countries as supportive nutrition along with orthodox cancer treatment, or supporting biological therapy of cancer. Paulino et al., here reviews his own propolis studies and many other peer reviewed publications on its pharmacological inter-and intracellular pathways. He will demonstrate that Baccharis dracunculifolia propolis can modulate interesting cellular targets in different cancer cells, such as nuclear transcription factor (NFκB); post translational prenylation in Ras-GTPase signalling; p38-MAPK, PI3K/Akt/PKB pathway; COX-2 and prostaglandin E 2 pathway; and iNOS or e-NOS expression and respective nitric oxide production. In addition, it modulates DNA fragmentation induced by cytochrome-C pathway; p53-protein signalling; releasing of pro-apoptotic proteins Bax and Bak; inhibition of neoangiogenesis by modulation of matrix metalloproteinases (MMPs) and vascular endothelial growth factor (VEGF) expression; control of the cell differentiation by modulating p21(Waf1/Cip1) protein in association with CDK2 and cyclin E. Finally, Baccharis dracunculifolia propolis has been used in associative therapy to improve the efficacy of chemotherapy drugs (e.g. combination with paclitaxel, resveratrol, vinorelbine, etc) while shortening treatment time and reducing treatment side-effects (with both synthetic chemotherapy and radiotherapy). Recently published results suggest that Baccharis dracunculifolia propolis can be used for supporting biological therapy or in association with chemotherapy drugs or radiotherapy, as a natural food supplement to help to treat or prevent cancer. Clinical and pharmacokinetics trials with animals and humans will be mentioned. Baccharis dracunculifolia propolis has been used in associative therapy to improve the efficacy of chemotherapy drugs (e.g. combination with paclitaxel, resveratrol, vinorelbine, etc) while shortening treatment time and reducing treatment side-effects (with both synthetic chemotherapy and radiotherapy). Recently published results suggest that Baccharis dracunculifolia propolis can be used for supporting biological therapy or in association with chemotherapy drugs or radiotherapy, as a natural food supplement to help to treat or prevent cancer. Clinical and pharmacokinetics trials with animals and humans will be mentioned.