Malignant mesothelioma usually presents as a diffuse neoplasm. We report a localized malignant mesothelioma in the parietal pleura of a patient who was not exposed to asbestos. A complete clinical, pathologic, and immunohistochemical description is provided. Flow cytometric analysis showed an aneuploid DNA content in neoplastic cells. The patient is alive and well 8 months after complete surgical resection. Localized malignant mesothelioma must be included in the differential diagnosis in chest wall-based neoplasms.