Endophytes have been known to confer resistance to host plants against insect herbivores mediated by fungal alkaloids. In this study we have isolated an endophytic fungus Nigrospora sp. (Ascomycota: Sordariomycetes) from a native plant Tinospora cordifolia. To assess anti-insect potential, we tested to what extent the survival and development of Spodoptera litura (Lepidoptera: Noctuidae), a polyphagous pest, was affected when fed on artificial diet amended with different concentrations of ethyl acetate extract of Nigrospora sp. In feeding assay, the insect suffered significantly higher mortality and showed prolonged development period on amended diet as compared to unamended diet. A significant reduction in relative growth and consumption rate, efficiency of conversion of ingested and digested food and approximate digestibility indicated deterrent as well as toxic effects of the fungal extract. Significant adverse effects were also observed on adult emergence, longevity and reproductive potential of S. litura. This preliminary information on insecticidal properties of Nigrospora sp. may further be used for imparting resistance in plants against insects.