The title compounds 2-substituted phenyl-3-{1-cyclopropyl-6-fluoro-7-[4-(4-methoxyphenylpiperazin-1-yl]-4-oxo-1,4-dihydroquinoline} carboxamido-1, 3-thiazolidin-4-ones 6a–j have been synthesized from lead molecule 7-chloro-1 cyclopropyl-6-fluoro-4-oxo-1,4-dihydroquinoline-3-carboxylic acid 1; this reacted with thionyl chloride to give acid chloride 2 and with hydrazine hydrate to afford hydrazide 3. The hydrazide 3 on condensation with substituted aromatic aldehydes a–j gave Schiff base; these on reaction with N-(4-methoxyphenyl) piperazine and thioglycolic acid furnished title compounds 6a–j. All of the synthesized compounds have been established by elemental analysis. IR and NMR spectral data and have been screened for antifungal and antibacterial activities.