This article examines the visions on nanosciences and nanotechnologies (N&N) disseminated by a group of Brazilian scientists to legitimize this emergent field of research. For this purpose we analyzed reports on N&N published by the Journal of Science, edited daily by the Brazilian Society for the Progress of Science, from 2002 to 2007, covering the period in which the main events in domestic N&N research policy took place. Our analysis shows that researchers on N&N are spreading visions of progress, efficiency and competitiveness related to the advances in this field, giving little attention to issues such as potential risks, and economic, social and ethical implications of these technologies.