Bioactivity-directed isolation has led to the isolation of (-)-ent-costunolide (1) as the major active compound from Hepatostolonophora paucistipula. This compound (1) was determined by spectroscopic data interpretation. This sesquiterpene lactone (1) inhibited the growth of the dermatophytic fungus Trichophyton mentagrophytes ATCC 28185, (4 mm inhibition zone at $15{mu}g$/disc), cytotoxic activity to murine leukaemia cell lines ATCC CCL 46 P 388D1 ($IC_{50}$ 687 ng/ml, at $0.075{mu}g$/disk), BSC monkey kidney cell lines (100% of well at $15{mu}g$/disk) and antiviral activity to Herpes simplex virus (0.25 mg/ml, 100% of well at $7.5{mu}g$/disk) and Polio virus (0.125 mg/ml, 100% of well at $3.75{mu}g$/disk). These results suggest that (-)-ent-costunolide (1) has potential antimicrobial and cytotoxic agents.