A novel synthesis of 4-acylthiosemicarbazone-3-methyl-1-(4`-methylphenyl)-2-pyrazolin-5-one by condensation of 4-acyl-3-methyl-1-(4`-methylphenyl)-2-pyrazolin-5-one with thiosemicarbazide is carried out. The compounds were characterized on the basis of elemental analysis, IR, 1H NMR, Mass, DSC and 13C NMR spectral data. The structures were investigated for their antibacterial and antifungal activity. They are very essential to study on cerebral infarction (Free radical scavenger). A single crystal X-ray study of this thiosemicarbazones and their metal complexes is in progress.