Objectives: In patients with unilateral auditory dysfunctions such as tinnitus and hearing loss, differential diagnosis of cochlear, retrocochlear, or vascular problems is important. Because unilateral hearing loss and tinnitus patients are increasing recently, screening tools are required. There are many diagnostic tests for differential diagnosis about patients with unilateral auditory dysfunction, but there is no efficient screening tool which can confirm all lesions. The purpose of this work is to assess the clinical usefulness of 3D fast imaging employing steady state acquisition (3D-FIESTA) sequence in unilateral hearing loss or tinnitus. Methods: Two hundred and sixty patients with unilateral tinnitus and hearing loss who underwent 3D-FIESTA temporal bone imaging were retrospectively analyzed, looking atmedical charts and radiologic reports. Otologic symptoms, which were measured based on pure tone audiometry results, were reviewed. We evaluated radiologic pathologic finding in the cochlear and retrochoclear areas. Results: Of the hearing symptoms, tinnitus comprised 49.6%, sudden sensory hearing loss, 31.9%, and unilateral hearing disturbance, 15.7%. Twelve patients were diagnosed with acoustic neuromas, four with enlarged vestibular aqueduct syndrome, two with posterior inferior cerebellar artery aneurysms, inner ear anormaly and vestibular cochlear nerve palsy each by 3D-FIESTA MR. Conclusions: 3D-FIESTA MR is highly sensitive and a cost effective method for differential diagnosis of hearing loss and tinnitus. 3D-FIESTA MR image is a useful diagnostic tool as screening for cochlear and retrocochlear lesions.