Recently, several authors have shown the benefits of homeopathy in improving the quality of lifeand survival of cancer patients. Preliminary data from the group showed that B16F10 murinemelanoma cells treated with Viscum album (Va), collected from the host tree Quercus robur duringthe Swiss summer (VaQr.s) and prepared in different homeopathic scales: 12 dH, 200 cH and 5 lmdecreased both viability and production of reactive oxygen species (ROS) and MCP-1 cytokine,when compared to B16F10 cells treated with the chemotherapy drug carboplatin. However, the invivo effects of these treatments have not been evaluated. Therefore, the aim of the present workwas to investigate the effects of different homeopathic preparations of VaQr.s in mice withmelanoma. For this, C57BL/6 mice were inoculated subcutaneously (s.c) on the left flank withB16F10 cells. After appearance of tumor nodule, mice were treated three times a week, orally,during 3 weeks with mother tincture (TM) or different potencies of VaQr.s (12 dH, 200 cH or5 lm). As controls, mice were treated with water or vehicle (10%-alcohol) or chemotherapy(carboplatin). Evaluations of the animals' general condition and tumor growth were performed onalternate days until approximately 30 days after tumor cell inoculation. The results obtainedshowed that mice treated with VaQr 12 dH or 5 lm have increased survival and body weight, aswell as a tendency to increase the quality of life of animals with melanoma, since these presentedless clinical manifestations when compared to the other treatments, mainly the carboplatin group.Together, the data presented here demonstrated for the first time, the effects of Va potencies onalleviating cancer-related fatigue in an in vivo model of murine melanoma. Furthermore, this workprovides relevant information for understanding the molecular events induced by homeopathicpreparations of Va as a support for future studies with ultradiluted Va