Fullerenols, the water-soluble derivatives of fullerenes, are currently being recently intensively studied in the context of the possibility of their application in the biomedicine. Due to their hydrophilic properties and the ability to eliminate free radicals, fullerenols may in the future provide a solid alternative to currently used pharmacological methods in chemotherapy, treatment of neurodegenerative diseases and radiobiology. Depending on the research protocol applied, fullerenols may also act as pro oxidants. The dualistic nature of fullerenols may contribute to finding new biomedical applications of these agents in the future, by exerting a cytotoxic or protective effect respectively against cancer cells or healthy cells. Because of the encapsulated structure of fullerenols, there exists the possibility of their application in medical diagnostics in the transfer of contrast agents or in the drug transport. During the planning of an experiment designed to investigate the effects of radiation in combination with derivatives of water-soluble fullerenes, the possibility of appearance of the “dose-response effect” should be taken into consideration since it significantly contributes to one of the two possible effects: protection or sensitization. The same applies to the possibility of using these compounds as potential neuroprotectors. Fullerenol may protect neurons in the particular areas of the brain but in the definedcertain doses it may also induce cell death. A giant leap in the field of nanotechnology not only leads scientists to search for new applications of nanomaterials such as fullerenols, but also raises the question about their harmful effect on the environment. High utilization of hardly biodegradable fullerenols increases the likelihood of their accidental release into natural systems and their bioaccumulation. Despite convincing evidences about the potential applications of fullerenols in biomedicine, we still have insufficient knowledge about the mechanism of action of these molecules and their possible side effects.