A 67-year-old female patient with biopsy proven AL systemic amyloidosis developed rapidly progressive dyspnea. Chest roentgenogram and CT scan revealed a large right pleural effusion in addition to nodular lesions with bilateral hilar lymphadenopathy. The patient's serum showed IgG lambda type monoclonal gammopathy and she also had Bence Jones proteinuria. The pleural effusion was an exudate that contained many mononuclear cells and a high concentration of protein. Cardiac function was not seriously disturbed. Except for amyloidosis, no other causes for the severe pleural effusion were found. This patient was treated with chemical pleurodesis using Picibanil and a low dose of prednisolone. Eighteen months after this treatment, her right pleural effusion did not recur. Bronchopulmonary tissues are known to be frequently involved by AL systemic amyloidosis, but a nodular pattern of pulmonary amyloid deposition and a unilateral large pleural effusion are rare clinical manifestations in this disease.