The problem of reducing the application of nitrogen fertilizers while maintaining satisfactory sugar beet yield has been under consideration for a long time. To maintain this proposition, the amount of nitrogen fertilizer may be reduced in proportion to the amount of nitrogen a sugar beet genotype is capable of receiving from selected Azotobacter strains. Our preliminary study 1991-1994 conducted under sterile conditions has been focused on specific relationships between Azotobacter chroococcum and sugar beet plants. The study included two commercial sugar beet hybrids and 12 Azotobacter strains of the 20 strains isolated from the rhizospheres of the hybrids. In the period of 1996-1999 the influence of three Azotobacter chroococcum strains on the production and technological characteristics of three sugar beet varieties was studied. It was shown that the yield of roots and sugar content and yield were positively affected by the inoculation of sugar beet seeds. When it is taken into consideration that increased doses of nitrogen fertilizer tend to increase sugar beet yield while reducing sugar content and other technological characteristics, it is important to mention that Azotobacter application maintains the root yield and sugar content while improving the technological characteristics. The microbiological fertilizer NS Betafixin is a liquid culture of Azotobacter strains isolated from sugar beet rhizosphere, which are capable of fixing the atmospheric nitrogen. The Federal Board for Approval of Microbiological Preparations has approved the production and commercialization of NS Betafixin.