Perilymph is considered the sole source of nutritional supply to the cochlear hair cells as well as the sole carrier for the elimination of metabolites. An increase of the perilymph turnover rate implies an improvement of the hair cell metabolism. Any drug that enhances perilymph production might be a useful agent for the treatment of acute inner ear lesions like sudden deafness, acoustic trauma and lesions following ear surgery. The influence of various pharmacological agents on the perilymph production rate is studied and their possible use for the treatment of inner ear affections is discussed. Vasodilating drugs failed to achieve significant production rises; favourable results were obtained with ergot alkaloides; most effective were plasma volume expanders and respiratory acidosis. In accordance with the assumption of different production modes (active secretion of cerebrospinal fluid; ultrafiltration of perilymph), perilymph production does not parallel with the cerebrospinal fluid in its pharmacological behaviour.