There are no previous descriptions of the preparation or properties of oligomeric products from the acid-catalyzed reaction of equimolar proportions of carbonothioic dihydrazide and dialdehydes. Di(alkylidene)carbonothioic dihydrazides are known as the products of the reaction of 1 or 2 mol monofunctional aldehydes [1–3] with 1 mol carbonothioic dihydrazide. The products of the reaction of 1 mol glyoxal bisulfite [4, 5] or kethoxal [5, 6] with 1 or 2 mol carbonothioic dihydrazide have been reported These products are soluble and do not have the properties of the oligomers described here.