Phytochemical investigation of n-butanol fraction of acetone extract of Aegle marmelos fruit has afforded four compounds coumarins marmelosin (1), marmin (2) and xanthotoxol (3) and flavonoid kaempferol 3- O-rhamnoside, afzelin (4). All the isolated compounds were evaluated for their antimycobacterium activity against Mycobacterium tuberculosis H37Ra and Mycobacterium bovis. Compounds 1 and 2 exhibited antimycobacterium activity against M. tuberculosis H37Ra with an IC50 12.46 µg/mL and 4.31 µg/mL respectively whereas, at 100 µg/mL, 62.5% and 82.4% growth inhibition of M. bovis was observed respectively. Compounds 1 and 2 were also evaluated against two gram positive bacteria Staphylococcus aureus, Bacillus subtilis and one gram negative bacteria Escherichia coli. Compound 1 at 100 µg/mL, showed growth inhibition, 64.6% and 74.9% of E. coli and B. subtilis respectively.