Sudden sensorineural hearing loss is a well recognized phenomenon in otologic practice with both viral and vascular etiologies being supported. However, sudden hearing loss as a complication of non-otologic surgical procedure is a seldom reported and rare phenomenon. Five cases of unilateral sudden sensorineural hearing loss which are time related and probably causally related to non-otologic surgery are presented. Two cases underwent open heart surgery and support previous reports of hearing loss secondary to cardiopulmonary bypass procedures. Three noncardiac cases are also reviewed. None of these patients had prior otologic disease which would predispose to a sudden hearing loss, and no intraoperative or postoperative complication was specifically noted as a cause of the hearing loss. The literature is reviewed and attention is drawn to the problem. We wish to encourage further reports and to recommend early identification and treatment in those cases related to cardiopulmonary bypass.