A bis-arylsulfonamide, 7, has been identified that exhibits growth inhibition of Mycobacterium smegmatis at less than 25 microg/mL, but has no such activity against Escherichia coli or Staphylococcus aureus. A closely related bis-arylsulfonamide (8) was much less active, but was the only other compound among 54 arylsulfonamides tested with detectable growth inhibition of M. smegmatis.