Background: Anacardium occidentale (cashew) is an economically important tropical plant valued for its edible nuts and numerous medicinal properties. Beyond the plant itself, its endophytic fungi have attracted increasing attention as potential sources of bioactive secondary metabolites with antioxidant and therapeutic applications. Despite the well-documented phytochemical and antioxidant properties of Anacardium occidentale, limited information is available on the phytochemical composition and antioxidant potential of its nut-associated endophytic fungi.Aims: This study aimed to evaluate the phytochemical composition and antioxidant activity of endophytic fungi isolated from Anacardium occidentale (cashew) nuts.Methods: Four endophytic fungal isolates (EF1–EF4) were cultured, and their crude extracts were subjected to qualitative and quantitative phytochemical analyses using standard procedures. Antioxidant activity was evaluated using the DPPH radical scavenging assay, IC₅₀ determination, and total antioxidant capacity assay.Result: All fungal isolates contained important bioactive phytochemicals and exhibited antioxidant activity. EF3 showed the highest levels of phenolics, tannins, and terpenoids, as well as the strongest antioxidant activity, with the lowest IC₅₀ value (47.55 µg/mL) and the highest total antioxidant capacity (112.83 mg AAE/g extract) among the fungal isolates.Conclusion: This research has identified novel fungal-derived natural antioxidants from Anacardium occidentale nuts with potential applications in the pharmaceutical, nutraceutical, and food industries.