Localized malignant pleural mesothelioma (LMPM) is an extremely rare tumor. We report the case of a 40-year-old Japanese male with an LMPM mimicking an anterior mediastinal tumor due to invasion to the anterior mediastinum, and we discuss mainly the differentiation of LMPM from an anterior mediastinal tumor. The present tumor had a long shape along the pleura, and LMPM could be one of the differential diagnoses.