2-Bisbenzothiazole-2,2’-disulfide was heated isothermally with and without sulfur at temperatures between 130 and 178 degrees C for various periods of time and the mixture analyzed by high-pressure liquid chromatography (HPLC). 2-Bisbenzothiazole-2,2’-monosulfide formed rapidly and 2-bisbenzothiazole-2,2’-polysulfides after an induction period of about 5 min. Polysulfides of higher sulfur rank are formed by the sequential addition of sulfur atoms. 2-Mercaptobenzothiazole catalyzes the formation of 2-bisbenzothiazole-2,2’-polysulfides and elimates the induction period. Mechanisms for the decomposition of 2-bisbenzothiazole-2,2’-disulfide and the catalytic role of 2-mercaptobenzothiazole are proposed.