Acute tubulointerstitial nephritis is associated with a variety of causes, such as drug interaction, and infectious or immunological mechanisms. We describe a patient who suffered from sepsis, septic shock, disseminated intravascular coagulation(DIC), hepatic failure and renal failure after receiving a bite from her house cat. The causes of her acute renal failure were initially thought to be due to circulatory failure with hypotensive shock, decrease in renal blood flow with fibrin formation by DIC, or microangiopathy such as hemolitic uremic syndrome. However, the renal biopsy on the 60th hospital day indicated tubulointerstitial nephritis, which was recognized by the presence of patchy and focal mononuclear small cell infiltration with invasion to the tubular epithelium. We concluded that prolonged renal failure was caused by tubulointerstitial nephritis. The cause of tubulointerstitial nephritis was not identified. Tubulointerstitial nephritis should be taken into consideration when the recovery from acute renal failure is slow.