The residues of metsulfuron-methyl in the soil can be a negative factor for the growth of susceptible crops to this herbicide. There are many successful examples of the use of bacteria to increase crop yields and protect plants against stress factors. The purpose of this work was to study the possibility of reducing the phytotoxic effect of metsulfuron-methyl in the soil on sugar beet using plant growth-promoting bacteria. Under greenhouse conditions, sugar beet seeds and bacteria were simultaneously placed in soil previously contaminated with methsulfuron-methyl. The weight of plants, leaf area, amount of proline, malondialdehyde, and flavonoids were measured. Suppression of the growth of young plants and oxidative damage caused by herbicides have been recorded. When sugar beet interacted with bacteria, Pseudomonas protegens DA1.2, oxidative stress caused by herbicide was mitigated, and the mass of plants increased. Treatment with bacteria against the background of herbicidal stress affected the dynamics of the content of flavonoids and proline, which play a role in the anti-stress reactions of plants.