Aims: To evaluate the phytochemical constituents and antioxidant properties of two selected mushrooms in Ibadan, Nigeria. Study Design: An experimental and descriptive study was conducted using the fruit bodies of Ganoderma lucidum collected from the Botanical garden University of Ibadan and Pleurotus pulmonarius which was bought from a local store in Ibadan. Successive extraction was done on the mushrooms with four solvents of increasing polarity that is from the non-polar (N-hexane) to a more polar solvent(water).Phytochemical and antioxidant analysis were then carried out on the extract fractions. Place and Duration of Study: Department of Botany, University of Ibadan, Ibadan, Nigeria and Department of Microbiology, University of Ibadan, Ibadan, Nigeria between May 2018 and February 2020. Methodology: The N-Hexane, Ethyl acetate, Ethanol and Aqueous extract fraction of Ganoderma lucidum and Pleurotus pulmonarius were analyzed in different system, including DPPH, Ferric ion Reducing Antioxidant Power (FRAP) and Total Antioxidant Capacity (TAC). The various antioxidant activities were compared to the standard ascorbic acid. Phytochemical include: Phenol, Alkaloids, Flavonoids, Tannins, Steroids, Saponins, Terpenoids Anthraquinones, and Cardiac glycosides were also analysed. Results: The Phytochemical screening result shows the presence of Phenol, Alkaloids, Flavonoids, Tannins, Steroids, Saponins, Terpenoids Anthraquinones, and Cardiac glycosides. The quantitative phytochemical screening revealed that the Ethyl acetate fraction of Ganoderma lucidum recorded the highest percentage of Alkaloids (41.70±0.14%) while the Ethanolic fraction of Pleurotus pulmonarius has the lowest percentage of Tannins (0.10±0.24%). DPPH scavenging activity of the Ethanolic extract fraction of Ganoderma lucidum (at 200 µg/ml) was 94.96% higher than that of Pleurotus pulmonarius (22.39%). The extract fraction of all the mushrooms possesses significant TAC content with N-Hexane and Ethyl acetate fraction having the highest. The results of the DPPH, FRAP, and TAC assays indicate that both mushrooms examined showed significant antioxidant activities. Among these, Ganoderma lucidum extract seems to be more effective antioxidant. The antioxidant activity of theses mushrooms has significant importance as it greatly contribute to their nutraceutical properties thus enhancing their nutritive value. Cultivation and production of dietary supplements from Ganoderma lucidum is highly recommended. Conclusion: The Mushrooms species analyzed have demonstrated to be good sources of phytochemical and antioxidants hence it can be recommended to pharmaceutical industries for the manufacturing of drugs.