This report presents a case of osteopetrosis in a 25-year-old male, which was complicated by the development of osteomyelitis in the maxilla and mandible following traumatic injury and tooth extractions. The osteomyelitis in the mandible was refractory to marginal resection and antibiotic therapy. Partial resection with mandible reconstruction was then carried out. Light and backscattered electron scanning microscopy revealed sclerosis of spongy bone and variations in mineral density of the bone matrix. There was also a prominent periosteal bone formation in regions affected by osteomyelitis. An 18-month follow-up showed absence of active infections in the face and oral structures, with a focal area of bone exposure in the right parasymphysis. However, development of anemia and bone marrow deficiency will likely affect prognosis. The importance of preventive oral health care and dental/periodontal managements in osteopetrosis is emphasized.