A total of 22 new heterocyclic hydrazones and their bioisosteric compounds were synthesized and evaluated for their activity against Mycobacterium tuberculosis, strain H37 Rv. All newly synthesized compounds showed inhibitory activities. Among these compounds,(1E,4E)-1,5-bis(5-bromo-2-thiophenyl)-1,4-pentadiene-3-one-(1,4,5,6-tetrahydro-2-pyrimidimyl)-hydrazone(1d) showed the most effective anti-tubercular activity with MIC90 value of 2 μg/m L, and exhibited an excellent inhibitory activity against isoniazi...