Abstract Experiments were performed to examine the effects of inoculation of two foxtail millet ( Setaria italica ) cultivars under humid and fertile conditions with various Azospirillum strains. In the first experiment the coinoculation with A. brasilense Cd+Az 39+ A. lipoferum Az 30 caused increases above control in the dry mass ofshoots by 30% in cv. Yaguane, in the presence of N applied at 0, 18.4 and 36.8 kg N/ha. Inoculation with Az 39 and Cd increased the forage dry mass by 21%. No significant differences were found in % N and number of tillers between control and inoculated plants. In the third experiment, on unfertilized soil, the bacterial inoculation caused a significant increase in shoot dry mass (57% with Cd and 91% with Cd+39). Our results show a positive field response of foxtail millet cv. Carape INTA and Yaguane INTA to inoculation with Azospirillum but the magnitude of yield increase depends on cultivar and the strain employed.