This report presents a case of primary intratesticular leiomyosarcoma. A 73-year-old male presented with a 6-year history of left scrotal swelling. A radiological examination revealed a left testicular tumour with multiple metastases in the lung, para-aortic lymph node and other organs. A radical orchiectomy was carried out and the pathology revealed an intratesticular leiomyosarcoma. The patient received additional chemotherapy. Cases of primary intratesticular leiomyosarcoma are rare. This is, to the best of our knowledge, only the tenth case of leiomyisaocoma in an adult reported in the literature, and the first case involving multiple metastases.