The study of the effect of biological preparations on the growth, development and yield of tomatoes was carried out at the experimental field of the Educational-Scientific-Practical Center of the Mykolaiv National Agrarian University in the conditions of the Southern Steppe of Ukraine according to generally accepted methods: field, laboratory and statistical. In order to study the elements of the technology of tomato cultivation with the use of organic technology, a two-factor field experiment was conducted in the conditions of the Southern Steppe of Ukraine: Factor A: cultivar: 1. Rio Fuego; 2 Missouri. Factor B: complex fivefold treatment with biological preparations: Azotophyt-r, FitoHelp, Organic Balance, Mycohelp, Actoverm, Lepidocide during the growing season: first - 12-14 days after the emergence of seedlings, then every 12-14 days. As a result of the conducted research, the effect of biological preparations on biometric indicators of plant growth and development, namely plant weight, above-ground height and root length as well as dry weight accumulation in the vegetative mass of Rio Fuego and Missouri tomato cultivars. The above-ground mass of tomato plants of the Rio Fuego variety in the flowering phase in the variant with treatment was 196.8 g piece-1, which exceeded the weight of the plant from the control variant by 38.2 g piece-1, or 24.1%. It was found that the use of biologics during the growing season of tomatoes contributed to an increase in the aboveground mass and a decrease in the percentage of roots to the total mass of the studied cultivars. The effect of biological preparations on the commercial yield of tomato fruit, which differed according to the years of research, was studied. The biologics used throughout the years with different agroclimatic conditions gave approximately the same results. The yield of the Rio Fuego cultivar increased in 11.1 Mg ha-1, or 24.9% due to the biologics. The Missouri cultivar turned out to be less productive throughout the years of research, but it was more responsive to the treatment with biologics, with the increase in the marketable fruit yield in comparison with the control being 10.9 Mg ha-1 (29.9%).