Adult-onset Still' s disease (AOSD) is an uncommon rheumatic disease characterized by high spiking fever, arthritis, an evanescent skin rash and variety of systemic symptoms, though initial onset of pleuropulmonary manifestation is relatively rare and could be responsible for a delay in diagnosis. We report a case of AOSD presenting with pleuritis with concomitant pericardial effusion. A 42-year-old Japanese man was admitted with a spiking fever of 40 degrees C, hyperleucocytosis (21.6 x 10(9)/l), and a high titer of C-reactive protein (16.84mg/dl). Chest X-ray film and computed tomography showed bilateral pleural effusion and massive pericardial effusion which both required tube drainage. Analyses of fluids revealed that both were exudative and sterile, and pleural biopsy showed nonspecific inflammation with mild fibrosis. Neither antibiotics nor antituberculosis drugs were effective. Rash, hepatosplenomegaly, polyarthritis, pharyngitis and right hypochondralgia were accompanied by serum hyperferritinemia. After exclusion of the possibility of infection, other connective tissue disease and malignancy, a diagnosis of AOSD was made. Improvement was not observed with nonsteroidal anti-inflammatory drug and corticosteroid therapy. Double filtration plasmapheresis (DFPP) following steroid pulse therapy alleviated the symptoms and the laboratory data immediately and corticosteroids could be tapered. DFPP is a safe therapeutic procedure and can be an alternative for refractory AOSD.