Background and aims <p>Biological nitrogen fixation (BNF) is a key factor in ensuring the sustainability of agricultural production and food security. This study aimed to estimate the savings generated by BNF in common bean (<i>Phaseolus vulgaris</i>), cowpea (<i>Vigna unguiculata</i>) and mung bean (<i>Vigna radiata</i>).</p> Material and methods <p>Data on the area, production and productivity of the crops in this study were obtained from the Brazilian agricultural censuses of 2006 and 2017. We estimated the amount of N (urea) necessary to produce 1000&#xa0;kg of grain of each bean species in the absence of inoculation. The contribution of BNF to the N supply of each legume species was obtained from studies using the ¹⁵N natural abundance method.</p> Results <p>We highlight that in Brazil, the savings generated by the BNF were US$6 million with mung beans, US$59 million with cowpeas, and US$119 million with common beans, in 2017. The savings generated by BNF per hectare planted with common beans in 2017 increased by 40% compared to 2006, mainly due to the significant increase of 64% in the grain yield of this crop.</p> Conclusion <p>Our study highlights the importance of BNF in the production of these pulse species that allows a reduction in the use of N-fertilizers and an increase in savings in these production systems, which contributes to sustainability of agricultural production.</p>