A simple and efficient method was developed for the synthesis of 2,6-disubstituted-imidazo[2,1-b][1,3,4] thiadiazoles under microwave (MW) activation using 2-amino-5-substituted-1,3,4-thiadiazoles and appropriate bromo ketones as materials. All reactions demonstrated the benefits of MW reactions: convenient operation, short reaction time, and good yields. All derivatives were characterized by IR, NMR, and Mass spectroscopy. Antibacterial and antifungal activity was performed using cup plate method against Staphylococcus aureus, Klebsiella, and Candida albicans microorganisms. 2-(4-nitro benzyl)-6-(4 bromo phenyl)imidazo[2,1-b][1,3,4]thiadiazole (4Ce) was the only derivative which showed activity against Klebsiella at low micromolar concentration (5 lg/ml) with moderate zone of inhibition. And 2-(4-nitro benzyl)-6- (4-fluoro phenyl)imidazo[2,1-b][1,3,4]thiadiazole (4Cf) as the most potent antifungal active derivative at 50 lg/ml against C. albicans on comparison to standard fluconazole.