This is a case report of simultaneous primary leiomyosarcomas in the spine and liver. A 64-year-old woman presented to the Seoul Paik Hospital with epigastric discomfort and constipation that she had experienced for two months. A physical examination revealed severe tenderness around the thoraco-lumbar junction. Esophagogastroduodenoscopy showed an ulceroinfiltrative lesion on the gastric angle. An abdominopelvic CT scan revealed two low attenuated lesions in the S4 and S8 regions of the liver, as well as a soft tissue mass at the T10 vertebra. Percutaneous ultrasonography-guided needle biopsy of the hepatic nodules revealed a leiomyosarcoma. The tumor at the T10 vertebra was removed to avoid spinal cord compression. The histology of this tumor was compatible with that of leiomyosarcoma. The potential primary sites for leiomyosarcoma, including the lung, thyroid, breast, kidney, genitourinary organs, and gastrointestinal tract, were subsequently investigated. No detectable abnormal findings that would suggest the origin of the tumor were found. Synchronous primary leiomyosarcomas in the spine and liver are quite rare and have a poor prognosis.