A study of the reaction between dilute aqueous solutions of hypo‐chlorous acid at initial pH's of 6.0 and 3.5 with 2,6‐dichloro‐ and 2,4‐dichlorophenol and 2,4,5‐trichlorophenol is described. Extensive chlorination and/or oxidation of the phenols is observed. Identification of the products showed that reactions which occurred involve chlorination to more chlorinated phenols, oxidation to chloro‐p‐benzoquinones, addition of chlorine to the aromatic ring to form chlorinated 2,5‐cyclohexadienones, and addition of 2 moles of chlorine or one each of chlorine and hypo‐chlorous acid to give cyclohexenone derivatives. Cleavage of the aromatic ring with loss of one carbon atom was also detected.