Smooth muscle neoplasms originating from the serosal membranes are extremely rare. Clinically they are usually silent, and they are mostly detected by chance only. They cannot be differentiated radiologically from othertumors of the pleura orthe chest wall. A definite diagnosis can be established only by histological examination. We report an additional case of leiomyoma of the pleura documented by light microscopy and immunohistochemistry. So far as we examined, the present patient is the third case of the leiomyoma of the chest wall.