AbstractPolyadditions of 1,6‐hexanedithiol and 1,10‐decanedithiol to divinyl sulfone (DVS) in hexamethylphosphoramide in the presence of triethylamine or potassium fluoride afforded polysulfone‐sulfides (IIIa and IIIb) with inherent viscosities as high as 0.8 dl/g. Polymerizations of other dithiols with DVS and distyryl sulfone (DSS) were also carried out, however, only low‐molecular‐weight polymers were obtained. A series of polymers derived from DVS were highly crystalline and soluble in hot dimethylacetamide and hotm‐cresol, whereas a polymer from DSS was quite amorphous and showed excellent solubility in a wide range of solvents. Polymers IIIa and IIIb had melting temperature