Primary cardiac sarcoma is an uncommon disease. In particular, leiomyosarcoma of cardiovascular origin is extremely rare. Half of all cardiac leiomyosarcomas are located in the left atrium. Due to the extreme rarity of left atrial leiomyosarcoma, there is no great experience in its management. This review includes a report of a case of left atrial leiomyosarcoma followed up over 45 months. The literature review examines the distribution of left atrial leiomyosarcoma, the physiological reasons for the tendency of cardiac leiomyosarcoma to be localized to the left atrial cavity, the clinical and physical appearance of this disease, and the key differences between left atrial leiomyosarcoma and the most common left atrial tumor, myxoma. The morphological features, using light and electron microscopy and immunochemical staining, are discussed. Treatment modalities including adjuvant therapy and surgical resection are examined and their effectiveness compared. Opinions regarding the results and optimal treatment of leiomyosarcoma are not always in agreement. This highlights the need for inter-hospital comparison to determine the optimal treatment regimen.