Here we report a case that was diagnosed as sarcoidosis but required differential diagnosis from pneumoconiosis. A 51-year-old asymptomatic man, who showed signs of bilateral hilar lymphadenopathy (BHL) on a chest X-ray taken during a medical check, was given a diagnosis of sarcoidosis, based on the results of mediastinoscopic mediastinal lymph node biopsy. Because of the presence of large and small nodular lesions adjacent to the pleura extending from the bilateral upper lobes into the lung field, and continuous bead-like, small nodular lesions in the right interlobar pleura, pleural sarcoidosis was suspected and thoracoscopy was performed. Macroscopically, multiple grayish-white nodules with distinct margins, up to 1cm in diameter surrounded by a proliferation of capillaries were found in the pleura, particularly in the upper lobes. Lesions were also scattered over the interlobar pleura and diaphragmatic surface. Histopathologically, several non-caseous epithelioid cell granulomas and silicotic nodule-like lesions of hyaline degeneration were found; therefore, pneumoconiosis, or more specifically chronic berylliosis, was suspected. Despite these symptoms, the patient did not have a history of exposure, and the results of the lymphocyte stimulation test using beryllium were negative in blood and bronchoalveolar lavage fluid. The patient was given a diagnosis of pleural sarcoidosis and has been observed without treatment.