Abstract: A process for the purification of crude 2-mercaptobenzothiazole, prepared by reacting aniline, carbon disulfide and sulfur at elevated temperature and pressure is described. The process comprises the reaction of crude 2-mercaptobenzothiazole with 5-20%, preferably 10-12%, molar excess aqueous alkali metal hydroxide having a concentration of 3 to 20% by weight alkali metal hydroxide at 70.degree. to 90.degree. C. for 0.5-4 hours, with vigorous agitation, followed by filtration of the insoluble impurities and acidification of the filtrate with a non-oxidizing mineral acid, such as hydrochloric and sulfuric acids. The precipitated, filtered product is washed with water and collected in 98-100% yield and 95-98.5% purity.