A 13-year-old boy who complained rapid swelling on the left side of mandible is presented. Histopathological examination revealed ossifying fibromyxoid tumor (OFMT). OFMT is a rare soft-tissue neoplasm that occurs usually in the subcutaneous tissue of the extremties. Head and neck involvement is relatively rare. In this case, we present the diagnosis, surgical treatment and long-term follow-up of an OFMT due to its unusual site of occurrence. The precise clinical behavior of atypical and malignant types of OFMTs is still unclear. Thus, histopathology report is important, leading surgeon to decide how often and how long to follow-up patient with OFMT.