Under field conditions in the Republic of Mordovia, we studied the effect of treatment of seeds and plants of winter wheat varieties Mironovskaya 808 and Skipetr with a complex biological preparation based on jointly cultivated strains PGPB Pseudomonas chlororaphis subsp. aureofaciens and PGPF Saccharomyces cerevisiae on plant growth and productivity. We used seed treatment with the biological preparation diluted with water at a ratio of 1 : 100, and plant treatment during vegetation at a dilution of 1 : 200. The complex biological preparation stimulated an increase in net productivity of photosynthesis and leaf surface, an increase in root dry weight and volume, but not plant height, and an increase in grain productivity by 25–36% compared with control. The stimulating effect of the biopreparation was variety-specific.