To provide a method of producing a 2-(arylsulfonyl)ethanesulfonic acid salt which is useful as intermediates for medicaments, agricultural chemicals, etc., and expressed by the general formula (2) [R1 and R2 may be the same to or different from each other, and are each H, a halogen, a lower alkyl, a lower alkoxyl, nitro, cyano, amino, a lower alkylamino, a di(lower alkyl)amino, acyl or an alkoxycarbonyl; and M is an alkali metal], capable of producing the product more efficiently than ever.

This method of producing the 2-(arylsulfonyl)ethanesulfonic acid salt expressed by the general formula (2) comprises reacting an aryl vinyl sulfone expressed by the general formula (1) with an alkali metal sulfite together with water in the presence of a solvent.