A novel series of 4-phenyl-9-(5-phenyl-[1,3,4-oxadiazol-2-yl)-1,6-dithia-4,9-diaza-spiro-[4.4]-nonane-3,8-diones (4a-e) in good to excellent yields by using commercially available 2-amino-5-phenyl-1,3,4-oxadiazole (1) as raw material and 2-chloro-N-(5-phenyl-[1,3,5]-oxadiazol-2-yl)-acetamide (2) and 2-benzylidene-3-(5-phenyl-[1,3,5]-oxadiazol-2-yl)-thiazolidin-4-onea (3a-e) as intermediates. The chemical structures of these compounds have been established by IR, 1 H, 13 C-NMR, Mass spectral data and elemental analysis. The newly synthesized compounds were screened for their ability towards antimicrobial activity.