Objective:To investigate the cytotoxic activity of endophytic fungi isolated from mangrove fungi.Methods:In the present study the DNA was isolated and the ITS region of 5.8s rRNA was amplified using specific primers ITS 1 and ITS4 and sequence was determined using automated sequencers.Blast search sequence similarity was found against the existing non redundant nucleotide sequence database thus,identified as Aspergilus flavus,Hyporcaea lixii,Aspergillus niger,Eutorium amstelodami,Irpex hydnoides and Neurospora crassa.Among the seven isolates, one fungi Irpex hydnoides was selected for further studies.The fungi were grown in sabouraud broth for five days and filtrate were separated and subjected to ethyl acetate for further studies. Results:Nearly half(49.25%) of the extracts showed activity(IC_(50) of 125 μ g/mL).These values were within the cutoff point of the National Cancer Institute criteria for cytotoxicity(IC_(50)<20 μ g/mL) in the screening of crude plant extracts.The GC MS analysis revealed that the active principals might be Tetradecane(6.26%) with the RT 8.606.Conclusions:It is clear from the present study that mangrove fungi with bioactive metabolites can be expected to provide high quality biological material for high throughout biochemical,anti cancer screening programmes.The results help us conclude that me potential of using metabolic engineering and post genomic approaches to isolate more novel bioactive compounds and to make their possible commercial application is not far off. Objective: To investigate the cytotoxic activity of endophytic fungi isolated from mangrove fungi. Methods: In the present study the DNA was isolated and the ITS region of 5.8s rRNA was amplified using specific primers ITS 1 and ITS4 and sequence was determined using automated sequencers. Blast search sequence similarity was found against the existing non redundant nucleotide sequence database thus identified as Aspergillus flavus, Hyporcaea lixii, Aspergillus niger, Eutorium amstelodami, Irpex hydnoides and Neurospora crassa. Among the seven isolates, one fungi Irpex hydnoides was selected for further studies The fungi were grown in sabouraud broth for five days and filtrate were separated and subjected to ethyl acetate for further studies. Results: Nearly half (49.25%) of the extracted showed activity (IC 50 (50) of 125 μg / mL). These values ​​were within the cutoff point of the National Cancer Institute criteria for cytotoxicity (IC_ (50) <20 μ g / mL) in the screening of crude plant extracts. GC MS an alysis revealed that the active principals might be Tetradecane (6.26%) with the RT 8.606.Conclusions: It is clear from the present study that mangrove fungi with bioactive metabolites can be expected to provide high quality biological material for high throughout biochemical, anti cancer screening programs. results of us us conclude that me potential of using metabolic engineering and post genomic approaches to isolate more novel bioactive compounds and to make their possible commercial application is not far off.