A benzenesulfonamide derivative represented by general formula (I) and a pharmacologically acceptable salt thereof, wherein R¹ represents hydrogen, lower alkyl, lower alkoxy or halogen; R² represents C₁-C₁₀ linear or branched alkyl, C₃-C₈ cycloalkyl optionally substituted by C₁-C₆ alkyl, C₁-C₆ alkyl substituted by C₃-C₈ cycloalkyl, 1-adamantylmethyl, 2-norbornylmethyl or phenyl-substituted C₁-C₆ alkyl which may be substituted on the benzene ring; R³ represents hydrogen or lower alkyl; and n represents an integer of 2 to 4. The compound has a thromboxane A₂ antagonism, a leucotriene antagonism, and so on, thus being useful as platelet aggregation inhibitor, antithrombotic, antiasthmatic, and antiallergic.