Solitary fibrous tumor of the pleura (SFTP) is an uncommon neoplasm. Surgery is the only curative therapy and provides a definitive diagnosis. Among these patients, malignant SFTP was reported having high recurrent rate and poor prognosis. Because of the rare incidence, the role of radiotherapy (RT) in the management of the disease has not been well defined. We reported a 50-year-old woman with malignant SFTP in the right thorax, which has been living free of disease for more than 2 years after surgery with microscopic residual disease and adjuvant RT. Adjuvant RT could be an option of treatment for microscopically residual disease of malignant SFTP following major surgery.