A 56-year-old female was admitted to the Department of Rheumatology, Peking Union Medical College Hospital with complaint of recurrent fever and acute lumbar pain. Fever was complicated with malaise, cough and occasional blood-streaked sputum. Lab tests showed elevated white blood cell count, increased serum creatinine, erythrocyte sedimentation rate and C-reactive protein. Other lab findings included severe anemia, hematuria, and proteinuria. Immunological examinations were positive for antinuclear antibodies, antineutrophil cytoplasmic antibodies and antiglomerular basement membrane antibody. Ultrasonography and CT scan detected a huge spontaneous perirenal hematoma at right side. Angiography revealed multiple microaneurysms on bilateral renal arteries and branches. A diagnosis of systemic vasculitis was suggested. Under the combination therapy of corticosteroids and cyclophosphamide, the patient presented sustained remission for one year. This case indicates that prompt and sufficient treatment of primary disease is essential to a promising outcome.