A 19 year old female was admitted to our hospital with complaints of fever, dyspnea and chest pain. Chest x-ray film showed a massive right pleural effusion. She was diagnosed to have systemic lupus erythematosus (SLE) because of malar rash, serositis (pleuritis), positive antinuclear antibody and positive anti-DNA antibody. Then she was successfully treated with 50 mg/d prednisolone. This case was unusual and of interest in that she had eosinophilia in the peripheral blood and exudative pleural effusion and a marked elevation of serum IgE level despite no history of allergic diseases and no evidence of parasite infections.