Actinomycete osteomyelitis is a rare infectious disease caused by actinomycetes infection of the bone marrow, cortical bone, and periosteum. This case is a 56-year-old middle-aged man who has been diagnosed with dental problems due to ulceration of the lingual l gingiva of the right lower molar and sharp bones. The patient did not have a history of smoking, drinking, chewing betel nut, and radiation therapy and did not take bisphosphonate. After clinical examination, gingival flap surgery was performed and local soft and hard tissue lesions were scraped. Histopathological examination confirmed actinomycotic osteomyelitis. No occurrence was observed after three months of treatment with oral antibiotic Amoxicillin 500mg q6h.