6-Methyl-2,4-heptandione (1) was coupled with diazonium salts of sulfanilamide (2) and 4-aminobenzoic acid (3). Resulting new hydrazones, namely 4-methyl-2-oxovaleraldehyde p-substituted phenylhydrazones 4 and 5, were refluxed with various hydrazines to synthesize the title compounds 6-15. Their structure elucidation was made on the basis of their analytical and spectroscopic data. The antibacterial activity was evaluated. Some of the compounds tested exerted moderate to potent antibacterial activity against Staphylococcus aureus, Staphylococcus epidermidis and Streptococcus pyogenes.