A 73-year-old woman with a 1-month history of dyspnea on exertion and a history of hypertension and hyperlipide-mia was referred for the evaluation of a left pleural effusion of unknown etiology. She had no history of malignancy. Diagnostic thoracoscopy under local anesthesia using a semi-rigid scope (LTF-240; Olympus, Tokyo, Japan) revealed numerous black tumors of varying size throughout the parietal and visceral pleura and the diaphragm surface (PictureA) and a large black-pigmented pleural tumor (PictureB). After a biopsy, a histopathological analysis of the mass and nod-ules revealed malignant cells with melanin-filled cytoplasm, indicating malignant melanoma. She was then referred to a dermatologist for systemic chemotherapy. Despite a thorough evaluation, no primary lesions were detected. Therefore , the most likely diagnosis was primary pleural mela-noma. Intrathoracic metastasis from melanoma is common, whereas primary pleural melanoma is extremely rare. Our patient had a pleural tumor diagnosed via thoracoscopy under local anesthesia showing massive black tumors spreading throughout the pleura. The authors state that they have no Conflict of Interest (COI).