A series of nine novel unsymmetrical bis-thiosemicarbazones were prepared in high yield by condensation of aromatic aldehyde thiosemicarbazones with indole-3-carboxaldehyde using microwave irradiation. The structures of the new compounds were characterised. Six of the compounds displayed varying levels of antibacterial activity against Escherichia coli, Bacillus subtilis, Pseudomonas aeruginosa and Staphylococcus aureus.