The nutritional composition, antioxidant, and biological properties of Terfezia boudieri Chatin, a desert truffle largely distributed in Egypt were evaluated. Carbohydrates were the most abundant macronutrients (15.4 g/100 g) followed by proteins (9.04 g/100 g), and ash and fat contents were 4.47 and 3.82 g/100 g, respectively. Arabinose was recorded in a high amount (3.02 g/100 g) while fructose was found in a small amount (0.2 g/100g). Citric acid is considered the main organic acid (5.03 g/100 g) while p-Hydroxybenzoic acid is considered the main phenolic acid (10.65 g/100 g) in T. boudieri (dry mass). Also, higher content of the essential linoleic, oleic, and palmitic acids (44.9%, 19.05%, and 11.38% respectively) were determined. Furthermore, the truffle extracts were tested for their antioxidant, antibacterial, and antifungal activities. Aqueous extract showed the highest antioxidant activity (IC50 value =221.9 µg) more than organic solvent extracts. Also, all Gram-positive and unicellular fungi (yeasts) exhibited the highest sensitivity to aqueous extract of T. boudieri while organic solvent extracts had great ability to inhibit the growth of Gram-negative and filamentous fungi.