Summary The contribution of Brazil to the database of the Institute for Scientific Information, ISI, has increased remarkably during the last years. Among the Brazilian research institutions, the publications of the University of São Paulo (USP) have been around 30& of the country's total publication within the ISI database. A similar share was found for USP's publications published in the 1980-1999 period and classified in the Life Sciences. This was observed in publications from both the highest impact factor journals and from those with the largest number of articles. We have found that the present share of USP's publications in some of the fields of the Life Sciences was much less than 30&, suggesting a gradual decentralization of the scientific activity in Brazil. The data point out that this set of USP's publications were concentrated in traditional and basic fields of biological research, where the focus is mainly oriented by international trends. The data suggest that USP's researchers have not been much devoted to some of the fields where research is oriented toward national issues.