The authors have analysed 15 cases of actinomycotic osteomyelitis of the mandible. Primary actinomycotic inflammation of the mandible was diagnosed in nine patients, secondary in six patients (following fracture or resection of the mandible). The diagnosis was established on the basis of the clinical examination confirmed by bacteriological and/or histopathological tests. The basic method of treatment was antibiotic therapy of long duration. Surgical treatment was performed in all patients. Twelve of fifteen patients who had received the therapy and proved asymptomatic for 1 year to 23 years were recognized to be cured of the disease. In three patients, a single recurrence of the disease was observed after 1.5–2 months.