The purpose of this research was to evaluate the biochemical composition and antioxidant activity of different natural preparations obtained from the yeast biomass of beer industry waste. It was found that the preparations had a valuable biochemical composition, high antioxidant activities, a broad spectrum of immunoactive and essential amino acids, and that their protein and carbohydrate contents varied depending on the extraction stage and solvent. In conclusion, the varied biochemical composition, significant antioxidant and enzymatic activities, the innocuousness of Saccharomyces yeasts for living organisms, suggest that the obtained preparations can be an excellent source of biologically active substances and that their high biological activity presents a considerable potential for animal husbandry, food industry and cosmetics.