Actinomycosis is a chronic granulomatous disease caused by the species of Actinomyces. Although it has become a rare disease in the present antibiotics era, it still needs long term antibiotic treatment and often mis- or delayed- diagnosed due to no typical sign and symptoms. Most often, it occurs in the cervicofacial region. Middle ear is not a common site for Actinomycosis, and the inner ear involvement is extremely rare. Here, we report a case of middle ear Actinomycosis involving facial nerve and lateral semicircular canal. Korean J Otorhinolaryngol-Head Neck Surg 2015;58(1):57-60