Since more environmentally friendly way of food production is being encouraged through sustainable agriculture, fertilization, plant protection and stimulation of physiological processes in plants using biologically active and environmentally friendly compounds like biostimulators, have an increasingly important role in the primary food production. However, physiological mechanisms of their activity are not fully understood as they contain a very large number of biologically active components whose individual impact on plant physiological processes has not yet been sufficiently explored. The study was conducted in order to examine the impact of five commercial biostimulators (Plantasalva with and without the addition of salt, Equisetum extract, Fermented plant extract, Biplantol), on the seed vigor indicators of garden cress (Lepidium sativum L.). The applied biostimulators significantly increased the germination of garden cress as compared to the control, while the most significant increase was recorded after seed was treated with Fermented plant extract. The highest fresh weight of seedlings, and also the lowest dry matter accumulation was observed in the treatment Plantasalva without the addition of salt. On the other hand, seed treated with Equisetum extract had the highest percentage of dry matter accumulated in seedlings, but also the lowest fresh weight. Treatments did not significantly affect the seedlings root elongation. According to the obtained results, it is difficult to distinguish which of examined biostimulator is the most effective and whose composition can influence the growth and development of seedlings the best. Therefore, further research should elucidate the exact mechanisms of activity of many physiologically active compounds that are contained in the examined biostimulators.