腎絲球腎炎是感染性心內膜炎一個重要的併發症。本報告介紹一名47歲女性病人，第一次住院時表現急性腎衰竭症狀，診斷為急性腎絲球腎炎，而投與免疫抑制劑治療；第二次住院表現為鬱血性心衰竭，才診斷出感染性心內膜炎合併腎絲球腎炎，經抗生素治療和人工瓣膜置換手術而痊癒。本病例值得注意之處有二：一、病人第一次住院時未接受抗生素治療，腎功能卻恢復至正常，可能與使用免疫抑制劑(prednisolone，cyclophosphamide)有關。二、此病人之C-ANCA為陽性反應。C-ANCA陽性通常存在於Wegener’s granulomatosis患者，而亞急細菌性心內膜炎合併腎絲球腎炎和C-ANCA陽性的關連，值得進一步研究。 Glomerulonephritis is an important complication of infective endocarditis. The purpose of this report is to show that a 47 y/o female patient presented with symptoms of acute renal failure in her first admission. The diagnosis was acute glomerulonephritis, and immunosuppressants were given. When she presented with symptoms of congestive heart failure in her second admission, infective endocarditis, complicated with glomerulonephritis was just diagnosed. She was then cured after antibiotics therapy and cardiac prosthetic valve replacement. There are two notable points about this patient. Firstly, the patient’s renal function returned to normal range without antibiotics treatment in the first admission. This might be the effect of immunosuppressants (prednisolone, cyclophosphamide) used. Secondly, the patient had a positive C-ANCA test. Since the positive C-ANCA test is usually found in patients with Wegener’s granulomatosis, the correlation between subacute bacterial endocarditis complicated with glomerulonephritis and C-ANCA is worthy of further study.