Natural products play a key role in meeting the global demand for new pharmacologically active substances. Endophytes, which live asymptomatically within living plant tissues, are an under explored group of microorganisms and hence studies on these microbes from unique ecosystems offer resources with immense biotechnological potential. In the present study an attempt was made to explore the bioactive potential of the endophytes residing in mangrove plants. These plants have already been reported to have bioactivities against different ailments. Among the 16 endophytic isolates screened, three bacterial and four fungal isolates showed antibacterial activity comparable to that of standard antibiotics. 3 fungal endophytes showed strong antioxidant activity compared to bacterial endophytes. Seven bacterial isolates and one fungal isolate were found to produce glutaminase free L-Asparaginase. One fungal isolate and three bacterial isolates showed significantly higher thrombolytic activity. Isolate RM-S-01 an endophytic bacteria isolated from the stem of the mangrove Rhizophora mucronata was found to be positive for all the four activities screened in the study. Therefore we conclude that these endophytes represent new sources of bioactive metabolites. Characterization of these endophytes and purification of active compound in the crude extracts need to be further researched on.