Introduction Soft tissue osteochondromas are rare benign tumors containing bone and cartilage that form in mesenchymal tissues with no connection to adjacent bone, cartilage, or periosteum. They mimic endochondral ossification and are usually encased in a fibrous tissue capsule. The occurrence of the tumor is extremely rare in the maxillofacial region. Case presentation A case of soft tissue osteochondroma in the submandibular region of a 47-year-old man with a medical history of muscular dystrophy and schizophrenia is presented here. The tumor had been gradually growing for 11 years before the patient's presentation to our clinics. Radiographic and clinical examination revealed a radiopaque mass in soft tissue that extended from the left anteroinferior border of the mandible and with no connection to the mandibular periosteum. Treatment involved surgical excision. A diagnosis of soft tissue osteochondroma was established by histopathological examination. Clinical discussion Previously, there have been only three reported cases of soft tissue osteochondroma in the maxillofacial region. The cause of this tumor is not clearly understood, with multiple hypotheses being proposed. Diagnosis usually involves radiology and histopathology, and the tumor is completely amenable to surgical excision. Conclusion Extraskeletal osteochondroma should be considered in the differential diagnosis of hard tissue lesions with no apparent connection to the underlying bone in the maxillofacial region. Although considered rare, clinical awareness about this tumor aids the practitioner in identifying, diagnosing and properly managing this tumor. There has been no report of recurrence or malignant transformation of the lesion.