Cemagref is a French public scientific research institute in agricultural and environmental engineering. Its scientific and technical community is multidisciplinary and consists of ten regional centers in France. Each center is equipped with an information service. Library professionals must offer Cemagref researchers homogeneous and efficient information services throughout the organisation. Tools offered by publishers for accessing scientific and technical information increase each year, and become more effective and more diversified. Resources are scattered . Researchers need to be directed to tools best adapted to their needs. Cemagref's library professionals concern is to identify tools, and to choose the most cost effective solution in collaboration with researchers. Working closely with researchers and having a good knowledge of their needs is a major advantage. This paper deals with the study methods and the results obtained in response to researchers information needs .