Malignant external otitis is severely extensive inflammation which was caused by Pseudomonas aeruginosa in elderly diabetic patients. In spite of continuous antibiotic therapy, the granulation tissue and necrosis rapidly developed at the bony and cartilaginous portion of external auditory canal, which may result in facial nerve palsy, mastoiditis, osteomyelitis of the skull base, and multiple cranial nerve palsy. Massive antibiotic therapy including blood sugar control and extensive radical mastoidectomy were required for this disease. Recently, the anthors experienced a case of malignant external otitis with multiple cranial nerve palsy. So we reported this case with review of literatures.