A 60-year-old stonemason, suffering for many years from joint pains and exertional dyspnoea, developed a high fever with weight loss. Physical examination revealed reddening of light-exposed skin areas, fine rales and overly warm and reddened hand and knee joints. Abnormal laboratory findings were increased erythrocyte sedimentation rate of 66 mm/h, C-reactive protein concentration of 1 mg/dl, haemoglobin of 9.4 g/dl and white cell count of 3300/microliters. Urine contained albumin (100 mg/dl) and cylinders. Titres of both antinuclear and anti-ds-DNA antibodies were elevated (1:2560 and > 97 U/ml, respectively). The chest radiography showed enlarged hili, as well as reticular and nodular shadows which histologically showed silicosis. Systemic lupus erythematodes was diagnosed and the patient was treated with prednisone (2 mg/kg daily), the dosage being reduced to 12 mg daily within 3 months. When the joint pains recurred, azathioprine (50 mg daily) was added for 24 months. At present he is receiving prednisone (12 mg daily) and there has been no recurrence for 4 years.