The incidence of renal impairment secondary to the abuse of analgesic compounds now accounts for a significant proportion of patients requiring renal replacement therapy. The clinical features of 100 cases of analgesic nephropathy are described; essentially these consist of otherwise unexplained renal impairment, urinary tract symptoms, radiological changes and sterile pyuria, often associated with dyspepsia, anemia and psychiatric disturbances. The classical pathological changes consist of interstitial nephritis and progressive reduction in renal size, secondary to repeated episodes of papillary necrosis. Cessation of analgesic abuse usually arrests the deterioration in renal function, and indeed some recovery of function may occur.