Global climate change, moisture deficiency, and the impact of various biotic and abiotic factors on agricultural crops increasingly hinder the realization of plant productivity potential. The use of controlled greenhouse conditions allows for a significant increase in crop productivity and protection from the adverse effects of environmental stressors. However, short crop rotations and year-round cultivation across two seasons create favorable conditions for the mass development of harmful organisms, necessitating the development of effective and safe control methods. This study presents the results of evaluating the effectiveness of biological plant protection agents based on microbial preparations and entomophagous under greenhouse conditions. The experiment included a comparison of four treatment options: Boverin BT + Liposam, Bitoxibacillin BT + Liposam, Actofit BT + Liposam, a complex of entomophagous, and an untreated control. The highest yield was achieved with the use of Boverin BT + Liposam (18.9 kg/m²). The variants using Bitoxibacillin (17.4 kg/m²), Actofit (16.5 kg/m²), and the entomophagous complex (16.1 kg/m²) also outperformed the untreated control (12.3 kg/m²) in terms of yield. The obtained data indicate that the use of biological preparations not only reduces the population density of phytophagous pests but also indirectly promotes plant growth and development, likely by enhancing nutrient uptake, increasing root system activity, and optimizing the physiological and biochemical status of the crop. The most effective preparations were those containing Beauveria bassiana, due to their ability to combine entomopathogenic activity with endophytic colonization of plants. The results confirm the effectiveness of biological products as components of integrated pest management (IPM) systems under conditions of restricted chemical pesticide use. The proposed protection systems can be recommended for implementation in commercial practice as part of sustainable vegetable production in Ukraine.