The study of the biological applications of fullerenes has attracted increasing attention despite the low solubility of the carbon spheres in physiological media. The organic functionalisation of fullerenes has helped solubilisation by covalent attachment of hydrophilic appendages. Therefore, recently synthesised fullerene derivatives reach satisfactory concentrations in water. However, the tendency of the fullerenes to form clusters is enhanced in polar media, where better solubilisation can be achieved by means of multiple functionalisation or using micellar systems. Once homogeneously dissolved, the fullerenes and fullerene derivatives exhibit an interesting range of biological activities, especially promising in the field of photodynamic therapy, HIV, neuroprotection and apoptosis.