To identify the most efficient bradyrhizobium strain for promoting soybean performance, a study was conducted in a growth chamber to assess five different inoculants and N fertilization. Soybean (Glycine max cv. Jutro) was subjected to inoculation with five bradyrhizobium strains viz DSM 1755, DSM 30131, DSM 1982, the multistrain DSM-MIX, a commercial peat inoculant, and to fertilization at 50 mg N kg-1 soil with Ca(N03)2,  in a completely randomized design with four replicates. At 81 days after sowing, soybean was harvested and assessed for its yield, and N2 fixation determined by N-difference method using wheat as reference crop. Dry matter, N and grain yield, nodulation and N2 fixation in N-fertilized soybean were lowest compared to any bradyrhizobium inoculations although these latter differed. The commercial peat inoculant performed significantly better than N fertilization with 20% and 260% increase in the rate and amount of N2 fixed respectively. Bradyrhizobium strains DSM 1755, DSM-MIX, and DSM 30131 are preferable to the commercial inoculant. Fertilization with 50 mg N kg-1 soil was deleterious to soybean, while combining 10 mg N kg-1 soil as N starter and bradyrhizobium strain inoculation significantly improved its yields, nodulation et N2 fixation. This practice deserves recommendation for soybean growing.