A series of new 3-hepta-O-acetyl-beta-D-lactosylimino-4-aryl-5-p-tolylimino-1,2,4-dithiazolidines were prepared by the interaction of hepta-O-acetyl-beta-D-lactosyl-3-aryl thiocarbamides and N-p-tolyl-S-chloroisothiocarbamoyl chloride. The structures of the products were confirmed by spectral methods. The products were assayed for their antibacterial and antifungal activities against some selected organisms. Some of the products displayed promising activity.