It forms white deliquescent sheet crystals or a white waxy solid that is soluble in water and ethanol, slightly soluble in benzene and insoluble in nonpolar solvents like diethyl ether.

Benzenesulfonic acid is prepared from the sulfonation of benzene using concentrated sulfuric acid: This conversion illustrates aromatic sulfonation, which has been called "one of the most important reactions in industrial organic chemistry".

Benzenesulfonic acid and related compounds undergo desulfonation when heated in water near 200 °C.

The alkali metal salt of benzenesulfonic acid was once used in the industrial production of phenol.

[6] A variety of pharmaceutical drugs are prepared as benzenesulfonate salts and are known as besilates (INN) or besylates (USAN).