Actinomycosis is a chronic, suppurative, granulomatous bacterial infection primarily associated with
Actinomyces israelii
. The condition can be categorized into three distinct clinical types based on the affected anatomical region: cervicofacial, pulmonary, or abdominopelvic actinomycosis. The standard treatment for actinomycosis involves antibiotic therapy, with an empiric penicillin regimen as the first-line approach. Surgical interventions comprise curettage of the affected bone, resection of necrotic tissues, excision of existing sinus tracts, and drainage of abscesses. These procedures are considered a last resort for cases of actinomycosis unresponsive to antibiotic therapy. In this context, we present a case of severely unresponsive actinomycosis that necessitated aggressive surgical resection of the infected mandibular bone, followed by immediate reconstruction using a fibula-free flap. The outcome yielded both favorable functional and aesthetic results.