A concern on the possible drawbacks of nanotechnology exists and, therefore, there is a need for accurate, reliable and unbiased information on the risks and benefits of this new technology. Public perception and the consequent attitudes toward nanotechnology is likely to be influenced by the correctness of the provided information on risks and benefits and, in turn, is likely to influence the realization of further technological advances. But are the needed information on risks of this emerging technology really available? Although the answer to this question is probably negative, several efforts have been made to study the toxicology of nanomaterials.