Department of Chemistry, Shri Radhakisan Laxminarayan Toshniwal College of Science, Akola-444 001, Maharashtra, India E-mail : pradip222091@yahoo.co.in 1,4-Bis-(3-arylimino-[1,2,4]-triazolo-[3,4-c]-[1,2,4,5]-dithiadiazin-6-yl)-benzenes have been synthesized by treating 1,4-bis-(4-amino-3-mercapto-4H-[1,2,4]-triazol-5-yl-benzene with N-aryl-S-chloro isothiocarbamoyl chlorides and then basification with dilute ammonia solution. Synthesis of 1,4-bis-(4-amino-3-mercapto-4H-[1,2,4]-triazol-5-yl-benzene was carried out by interacting the terephthalic acid dihydrazide with carbondisulphide in presence of potassium hydroxide and then by adding the hydrazine hydrate. Bis-triazolo-dithiadiazines on acetylation afforded di-ace tyl derivatives. Structures of title compounds were delineated on the basis of determination of equivalent weight, chemical transformation, elemental analysis and spectral studies. These compounds have been assayed for their antibacterial and antifungal activity against various micro-organisms.