Actinomycosis is a rare form of disease that is caused by Actinomyces such as A. israelii and A. bovis, which may take the form of chronic, purulent inflammation of deep tissue evolves with necrosis, formation of sinuses and fibrotic mass. This disease arises in the head and neck area mainly in 55% and other places like that chest and the gastrointestinal tract occurs in 45%. Actinomycosis can present in a variety of forms and may mimic other infections or even neoplasms. Our case was 44-year-old man having painful indurated mass in his left TMJ area, otorrhea in his left ear and trismus. He was treated with surgical excision and biopsy confirmed actinomycosis. And after that, he was cured successfully with antibiotic therapy. We report this case of actinomycosis that developed in the left TMJ area with review articles.