The present investigation is a novel approach of exploring the endophytic fungal diversity of Elaeagnus latifolia L., an actinorhizal plant species of North-east India and evaluation of its biocontrol potential against Pestalotiopsis theae, the causal agent of grey blight disease in tea. A total of 17 endophytic fungal species belonging to 12 families and 03 orders were isolated from various parts of E. latifolia L. Isolates were identified based on colony morphology, spore and fruiting bodies using microscopical tools and techniques. Nigrospora sp. showed highest species density (0.5) among all the isolates. Isolation frequency was maximum (67%) in case of Fusarium sp., Nigrospora sp., Penicillium chrysogenum and Rhizopus sp. More fungal isolates were obtained from root and stem (47% each) as compared to leaves (29%). Species richness and diversity indices was maximum (15.0) in stem and minimum (9.0) in leaves. Highest Shannon and Simpson diversity index was in stem (2.02 and 0.860 respectively) followed by root (1.979 and 0.847 respectively) and least in leaves (1.494 and 0.75 respectively). Among the isolates tested for plant growth promoting parameters, EF09 (Fusarium sp.) showed positive response for all the tested parameters. The isolate, EF09 also showed maximum antifungal potential (up to 87.1%) against P. theae in poisoned food technique. Enumeration of endophytic fungal diversity of E. latifolia L. holds promises as the putative strains may lead to the isolation of novel bioactive components for use in industry, medicine and agriculture.