AbstractBrazil is one of the developing countries that made significant progress in biotechnology during recent years. The Brazilian Agricultural Research Corporation (Empresa Brasileira de Pesquisa Agropecuária - Embrapa), affiliated with the Ministry of Agriculture, state research institutes and universities are producing the most important and more productive work in agricultural biotechnology research. The preliminary ex ante impact evaluation of the main research projects developed by Embrapa in biotechnology shows that the social and economic benefits are potentially high. Biotechnological research conducted by the institution is in an advanced stage of development and certainly in the next few years should generate new, more productive varieties that use less inputs and have improved resistance to diseases and herbicides. Because of the introduction of new characteristics oriented to the quality of nutrition and to health improvement and because of positive changes in the social relationships when the whole food chain is considered, these new biotech products, to be released by the Embrapa centres, most likely will also generate important social benefits for small producers and for consumers as well. Potential benefits estimated for each one of the five commodities (soyabeans, cotton, potatoes, papaya and beans) included in this study showed that the amount spent annually, directly and indirectly, by the Brazilian society through the Embrapa biotechnology programme (around US$14.4 million, in 2000) will generate high returns. Only the economic impacts expected from the new transgenic varieties of beans will be enough to compensate these investments. In the same way, the social and environmental impacts expected based on preliminary evaluation present a good perspective to be positive and important for consumers and for small producers as well. It should be emphasized that Embrapa's biotechnology research programme is in its first stages of development and that the perspectives to obtain more expressive results in the future are very high given the projects in progress and the effort to build a new institutional research and development agenda. Investment in human resources, especially in training in this area, continues to be a main priority and investments in infrastructure (laboratories and equipment) made recently or planned for the near future are also important and justify the expectation of significant results.