Myofibroblastic sarcoma is a rare tumor that mostly develops in the soft tissues of the head and neck. Within the oral cavity, a tongue lesion is the most common. A myofibroblastic sarcoma tends to recur locally instead of metastasizing. We encountered a myofibroblastic sarcoma of the mandible of a 9-year-old male and performed mass excision and additional marginal alveolectomy. So far, there is neither recurrence nor metastasis. We report this case because of the uncommon location of this tumor type and its surgical approach compared to other forms of sarcomas.