A Series of 5-[(2'-N-sub.arylidene hydrazinothioacetyl)-1-(methylene)-1,'3'4'-thiadiazoles]-1,2,3-benzotriazoles 3a-k and 5-[(2'''sub. Aryl-1''',3'''-thiazolidine-4'''-ones)-1''-(iminothioacetyl)-1-(methylene)-1,'3'4'-thiadiazoles]-1,2,3-benzotriazoles 4a-k, were synthesized by using 5-[2'-Marcapto-1-(methylene)-1,'3'4'-thiadiazoles]-1,2,3benzotriazoles as the starting material. The Structure of the synthesized products were assigned on the basis of elemental analysis, IR and 1 HNMR spectral data. All the products were screened against different strains of bacteria and fungi.