The toxicity of C60(OH)30, C70(OH)30, and C120O(OH)n fullerenols, prepared by a new original method, has been studied. This method allowed us to obtain high-purity fullerenols and eliminate the risks of synthesis of preparations containing insoluble fractions contaminated with impurities such as fullerenes not completely reacted by hydroxylation. All fullerenols were detected inside cultured cells. The MTT assay as well as the analysis of apoptosis and cell cycle showed that С60(ОН)30 and С70(OH)30 are non-toxic for cultured V79 и HeLa cells at concentrations exceeding physiological levels by an order of magnitude. С120O(OH)n caused low toxicity. Studies in Drosophila melanogaster showed that any preparations used did not result in a decreased lifespan or in behavior abnormalities in flies.