Malignant external otitis is an infectious disease of the external auditory meatus caused by the Pseudomonas aeruginosa organism and mainly affecting elderly diabetics and immunosuppressive patients. It typically consists of wide infections of the external auditory meatus and responds poorly to general treatment. It not properly treated, it leads to facial nerve palsy, mastoiditis, sepsis, osteomyelitis of the skull base, multiple cranial nerve palsies and even death. Recently, the authors experienced a case of malignant external otitis diagnosed by clinical features, temporal bone CT scan, Tc-99m bone scan and Ga-67 citrate scan. The result of treatment was observed by Ga-67 citrate scan, so we reported this case with review of the literature.