Hydroponics offers a viable solution for obtaining plant products that are rich in micronutrients and ultramicronutrients, such as selenium. Selenium plays a crucial role in strengthening the body's immune defense and acts as a potent antioxidant. Low levels of selenium have been associated with an increased risk of heart attacks, strokes, and cancer. Stevia rebaudiana Bertoni (SrB), a relatively new crop in plant cultivation, was the focus of the present study. SrB has numerous medicinal and prophylactic properties, and its leaves are rich in macro- and microelements, vitamins, and diterpene glycosides. These diterpene glycosides, when extracted from the plant material, exhibit a sweetness that is 200-300 times greater than that of sugar. The study aimed to investigate the effects of exogenous application of varying amounts of selenium to the nutrient solution and foliar feeding of SrB plants with a selenium aqueous solution. The productivity of SrB and selenium accumulation in the leaves were assessed under both hydroponic and soil cultivation conditions in the Ararat Valley. Comparative analyses were also conducted on biometric and biochemical indicators, as well as the productivity of SrB cultivated using different fillers, including black volcanic slag, red volcanic slag, and gravel, in hydroponic and soil environments. The findings of this research hold practical significance as they serve as a foundation for the development of biotechnological approaches to enhance selenium enrichment in various crops. By applying these strategies, crop cultivation methods can be improved, and the selenium content in plant products can be enhanced. This optimization of crop production techniques can increase the nutritional value and potential health benefits of selenium-enriched plant products.