Abstract: The spirooxindole-pyrrolothiazole heterocyclic hybrids are compounds having the formula: wherein R is hydrogen and R? is fluorine (compound 6a) or R is fluorine and R? is hydrogen (compound 6b). The hybrids may be obtained using a chemical synthesis process involving 1,3-dipolar cycloaddition of 3,5-bis(4/2-fluoro-benzylidene) piperidin-4-ones with isatin and 4-thiazolidinecarboxylic acid in a suitable solvent, preferably 1-butyl-3-methyl-imidazolium bromide (“[bmim]Br”), and preferably under microwave irradiation. Both of these new hybrids demonstrate antimicrobial activity against both gram positive and gram negative drug resistant and non-resistant bacterial pathogens, although compound 6a exhibits more potent antibacterial activity than compound 6b.