OBJECTIVES:: To assess long-term vertigo symptom control in patients after intratympanic gentamicin instillation for incapacitating unilateral Méniére's disease. To analyze whether an absent caloric response, as analyzed using electronystagmography after gentamicin treatment, is a good predicator of long-term symptom control. Finally, to quantify the patient's perception of long-term posttreatment handicap. STUDY DESIGN:: A retrospective study from a single institution. All patients underwent a similar fixed-dose and duration protocol of drug instillation. METHODS:: Patients were enrolled in this study, and initial outcomes were assessed according to the American Academy of Otolaryngology-Head and Neck Surgery Committee on Hearing and Equilibrium Guidelines for Reporting Treatment Results in Méniére's Disease (1985 and 1995). In this study, only those patients treated more than 5 years previous were considered. One hundred thirty-two patients were eligible for inclusion. All patients underwent hearing testing and electronystagmography, including caloric testing before and after treatment. Posttreatment handicap and long-term vertigo control were assessed using the Dizziness Handicap Index questionnaire expanded with 5 questions specific for Méniére's disease. RESULTS:: Analysis of results is based on the 63 patients who responded. Forty-four were vertigo-free, whereas 14 continued to experience some degree of vertigo. On average, they described 5 episodes in the immediate 24 months before the study. Of the 44 patients who were asymptomatic, 35 had an absent caloric response. Of the 14 patients who realized some vertigo, 12 had an absent caloric response posttreatment. Of the 63 responders, 44 filled in the Dizziness Handicap Index. Of the 19 who did not, 17 reported that they were vertigo-free. CONCLUSION:: Our current protocol achieves complete or substantial vertigo control in most patients. A significant caloric response reduction has been a consequence in almost all patients, although an absent caloric response is not invariably a predictor of long-term symptom control. Finally, patient-perceived handicap in this long-term follow-up is consistent with that of others followed for a much shorter duration in that those who were vertigo-free volunteered a significantly lower score.