Objectives: The present study aimed to investigate and isolate different phytochemical constituents and assess the antioxidant, antimicrobial and cytotoxic activities of the total methanolic extract and different fractions of Chrozophora oblongifolia root bark. Methods: Phytochemical screening of Chrozophora oblongifolia was performed using specific test for each class of compounds. Different chromatographic techniques were used to isolate and purify compounds and their structures were elucidated by using different 1D-NMR spectroscopy (1 H NMR and 13 C NMR). The antioxidant activity was evaluated using DPPH radical scavenging assay, antimicrobial activity was done by standard agar well diffusion assay and cytotoxic activity was performed by using MTT colorimetric assay method. Results: Phytochemical investigation of chrozophora oblongifolia revealed the presence of carbohydrates and / or glycosides, sterols and or triterpene, alkaloids, tannins and saponins and the absence of flavonoids and anthraquinones. After fractionation, methyl gallate (1), gallic acid (2) and β-sitosterol-3-O-β-Dglucopyranoside (3) were isolated from ethyl acetate fractions. The result of the antioxidant activity showed that, the ethyl acetate fraction showed highest antioxidant activity followed by n-butanol and total methanolic extract. The result of the antimicrobial activity showed that, the total methanolic extract and ethyl acetate fraction showed moderate activity against Staphylococcus aureus, Vancomycin resistant Staphylococcus aureus and Candida albicans. The result of the cytotoxic activity showed that, the methylene chloride fraction followed by the total methanolic extract showed the highest cytotoxic activity against (MCF-7 and Huh-7) cancer cell lines. Conclusion: The root bark of Chrozophora oblongifolia is a rich source of different classes of active constituents as phenolics. The total extract and some fractions of Chrozophora oblongifolia showing antioxidant and antimicrobial and cytotoxic activities.