Jet irrigation is an accepted method for removal of cerumen from the external auditory canal. Even at a submaximal power setting, oral jet irrigators can generate enough force to rupture the tympanic membrane. Parameters for safe use of these irrigators have never been established. Three cases are reported in which, in addition to tympanic membrane rupture, oral jet irrigators caused ossicular disruption, round and oval window fistulae, and subluxation of the stapedial footplate. A prospective study performed on 25 fresh cadavers demonstrated a 6% incidence of tympanic membrane perforation when the power setting was one-third full power or greater. Recommendations are made for safe use of oral jet irrigators for removal of external auditory canal cerumen.