The use of a polymaleinate glass ionomer cement in 80 neuro-otology cases is described. It has pf oved of great value in translabyrinthine acoustic neuroma surgery, reducing the incidence of CSF fistula to nil. It is the method of choice for fixation of the Nucleus cochlear implant, and has many other applications in the field of otology and neuro-otology. It is easy to use and appears to have no side effects.