Metastatic carcinoma of the temporal bone is uncommon, with breast, lung, kidney and prostate being the most common metastatic primaries. Typical symptoms of metastatic carcinoma of the temporal bone include hearing loss, paralysis of facial nerve, earache, vestibular symptoms and preauricular swelling. Herein we reported a patient with temporal bone metastasis of prostate cancer in mastoid which caused subtle inflammatory middle ear disease and manifested with symptoms mimicking serous otitis media.