Medicinal leeches (Hirudo medicinalis) and the native secretion of their salivary glands diluted with saline (5 times) were successfully used for the treatment of some ear diseases: tinnitus caused by inner-ear affections, acute external otitis and chronic otitis media. The effect of diluted leech saliva injected into the region of the mastoid process by microelectrophoresis was 25-30% lower than that of the medicinal leeches.