ABSTRACT Objectives: To discuss the transmastoid partial labyrinthectomy approach for brainstem vascular lesions, with respect to hearing and balance preservation. Design: Retrospective case series. Setting: Tertiary referral center (University Health Network, Toronto). Participants: Nine consecutive surgical patients between 1999 and 2004. Main outcome measures: Clinical, audiometric, and electrophysiological vestibular data. Results: Nine transmastoid partial labyrinthectomy procedures (all females) were performed. In seven patients the underlying pathology was an intra-axial brainstem cavernous malformation. Two patients were treated for a basilar artery aneurysm. All patients had progressive neurological signs. Serviceable hearing (pure tone average (PTA): < 50 dB; speech discrimination score (SDS): > 50%) was preserved in seven patients. Partial vestibular function (clinical and electrophysiological) was maintained in most patients. Conclusions: The partial labyrinthectomy approach to the skull base provides excellent exposure while preserving cochleovestibular function in most patients.