In this review, we examined a 45-year-old Asian man who had been diagnosed with florid osseous dysplasia (FOD) of the mandible and acute perimandibular cellulitis. This presentation occurred after a history of off-and-on swellings of the jaw and multiple treatments received at another hospital. An aggressive resection of the jaw was planned; however, the patient denied the treatment and came to our clinic to seek a second opinion. The patient was successfully treated by conservative surgery and antibiotic treatment with preservation of the jaw integrity and the mandibular neurovascular canal. Intraoperatively, a piece of a calcified mass was removed and submitted for histopathological examination. The specimen showed woven bone and densely sclerotic mass of calcified materials exhibiting reversal lines and inflammatory cell infiltration of the connective tissue. The definitive diagnosis was FOD with a secondary infection. Treatments for FOD were discussed.