A new series 3-{2-[N′-(1,3-disubstituted-1H-pyrazol-4-yl-methylene)-hydrazino]-thiazol-4-yl}-chromen-2-one (10a–l) was synthesized by a multi-step reaction. All the synthesized compounds were characterized by IR, NMR, and mass spectral studies, followed by elemental analysis. The newly synthesized thiazole compounds were screened for their in vitro antibacterial and antifungal studies against various microorganisms. Antimicrobial studies carried out by the well diffusion method, showed a very good zone of inhibition for both bacteria (at a range of 20–50 mm diameter) and fungi (at a range of 10–30 mm diameter). Minimum Inhibitory Concentration (MIC) required for the 100% inhibition of bacteria and fungi was found to be as low as 15.6 μg ml−1 for a few of the synthesized compounds.
