Legumes (Leguminosae) are one of the most widely grown crops in the world after cereals (Poaceae). They are not only an important source of protein in food and feed, but also a significant component of different agrosystems. The N2 fixation by legumes is of great importance in nutrient management and sustainable economy of nitrogen. Legume productivity largely depends on a successful formation of symbiosis between the plant and soil microorganisms. The most important among those are rhizobia and mycorrhiza fungi. The field experiment was carried out at the Institute of Soil and Plant Sciences, Latvia University of Agriculture in 2014 to evaluate the influence of double inoculation using rhizobium leguminosarum and mycorrhiza fungi preparation on yield formation of broad bean V. faba L. var. major Harz ‘Bartek’. The bean seeds were treated with rhizobia and/or mycorrhiza fungi before sowing. Seeds were treated with rhizobia by soaking in bacteria suspension for 30 minutes directly before sowing. Mycorrhiza fungi preparation was added in soil under seeds before sowing. Plant height, fresh and dry weight and the weight of nodules were measured at the beginning of broad bean flowering (BBCH 60-61). rhizobium leguminosarum response to double inoculation differed between the strains. Rhizobium leguminosarum strain RL407, isolated from Vicia faba, was shown to be the most appropriate strain used for inoculation of broad bean seeds. Bean seed double inoculation increases the protein content significantly comparing to single inoculation using mycorrhiza fungi preparation.