Leiomyosarcoma (LMS) is a malignancy which very rarely occurs in maxillofacial location, and the course of the disease is not very characteristic.In this case report, we present a 58-year-old female patient with a painless tumor of the left angle of the mandible causing slight asymmetry of the face. She also reported that she observed deterioration in fitting of the lower denture in the oral cavity for several months, which she had used successfully for 5 years.On the basis of clinical tests, histopatological examination, and imaging (CT, MRI, ultrasound, pantomography), the patient was diagnosed with primary malignant leiomyosarcoma (LMS) of the mandibular corpus and ramus on the left side. The patient received combined surgical and oncological treatment. The first stage was a surgery, and then adjuvant radiotherapy was applied on the site of the resected tumor-a total dose of 60 Gy in 35 fractions. The patient's postoperative course was uneventful. She also underwent adjuvant therapy well. In the period of 3-year follow-up, no signs of recurrence were observed.The findings may extend our knowledge and experiences in the treatment of leiomvosarcoma in the craniofacial area.