Risk factors and complications in immediate implant placement are widely discussed. The present report describes a case of severe osteomyelitis as a serious complication after the immediate placement of a dental implant into an extraction socket of a 61-year-old woman. The course leads from initial treatment of recurrent perimandibular abscesses with surgical drainage and high-dose intravenous antibiotics to a refractory osteomyelitis. Hemimandibulectomy and partial mandibular reconstruction with a free fibular flap followed.