Terminalia bellerica (Roxb.) is an important indigenous deciduous medicinal plant and its fruit is an important ingredient of herbal formulation ‘Triphala’. In our study, we isolated compound luteolin 7-O-a-L-rhamnopyranoside from the chloroform: ethyl acetate [in the ratio of 70:30] fraction of 95% ethanolic extract of Terminalia bellerica heartwood. Further studies indicated that luteolin 7-O-a-L-rhamnopyranoside has an anti-bacterial effect against Escherichia coli, Salmonella Stanley, Bacillus anthracis and Klebsiella pneumonia. In addition to that luteolin 7-O-a-L-rhamnopyranoside has an anti-fungal activity against Aspergillus niger, Aspergillus flavus, Chrysoporium tropicum. The results in the present study clearly indicate that the isolated compound possess potential broad spectrum antimicrobial activity.