This invention relates to novel benzisoxazole derivatives that are found to be potent modulators of potassium channels and, as such, are valuable candidates for the treatment of diseases or disorders as diverse as those which are responsive to the modulation of potassium channels e.g. a respiratory disease, epilepsy or convulsions. X represents a substituent selected from the group consisting of CO—NR′R″, CO—O—R′, CO—NH—S, CO—NH—SO2R″′, CO—NH—C═N, SO2—NR′R″, 2,3-dihydro-1-H-tetrazol-5-yl and [1,2,4]oxadiazolidin-5-one; wherein R′ and R″, independently of each other, represent hydrogen or alkyl or phenyl; and R″′ represents alkyl, cycloalkyl, haloalkyl or phenyl, which phenyl may optionally be substituted one or more times with substituents selected from halo, trifluoromethyl, trifluoromethoxy, cyano and nitro.