Recently, we have carried out operationally simple, efficient, one pot synthesis of 2,3- diaryl-1,3-thiazolidine-4-ones by condensation of substituted aromatic amines and aldehydes in presence of thioglycolic acid with solid catalyst anhydrous zinc chloride in dioxane by microwave irradiation for 10 min. The yields of the products were excellent. The structure of the synthesized compounds has been established on the basis of IR, NMR, C13 NMR spectroscopic techniques. The antimicrobial activities of the synthesized compounds were tested in vitro against the sensitive organisms Staphylococcus aureus (Gram positive bacteria) and Escherichia coli (Gram negative bacteria) by using the disc diffusion method.