Since the 1950s, much research effort has been devoted to identifying and measuring the contribution of technical progress to agricultural growth. More recently, attention has also been focussed on the distributional impacts of technological change in agriculture. As a reflection of this worldwide tendency, reinforced by the problems faced by the economy in recent years, research and extension resource allocation began to generate increasing interest in Brazil. This paper contributes to this research. Specifically, the effects of investment in research and extension on total agricultural production and on production of individual crops will be studied. Some distributional effects will be briefly discussed. Due to the lack of data, the first part of the analysis will be restricted to the State of Sao Paulo, and the second part will cover the entire country.