 This review covers the history on biological nitrogen fixation, BNF, and graminaceous plants grown in Brazil. It describes research progress made over the last 40 years, most of which coordinated by Johanna Doberreiner. The role of these diazetrophs in association with grasses, mainly with cereal plants, has been studied. This article was authored by Jose I. Baldani and Vera LD. Baldani.