Heroin addiction is associated with several severe and occasionally fatal renal complications. Acute renal failure consequent to rhabdomyolysis and myoglobinuria, when treated supportively, carries a good prognosis. Staphylococcal or other bacterial septicemia may in itself prove fatal and is associated with a proliferative immune complex, acute glomerulonephritis, which generally follows the course and prognosis of septicemia. The necrotizing angiitis reported in heroin addicts still is largely undefined. Focal and segmental glomerular sclerosis is the most common pathologic finding in the syndrome of heroin-associated nephropathy (HAN). Typically, HAN presents with massive proteinuria and progresses rapidly to renal failure. Presumptive evidence supports the premise that heroin or its vehicles elicits immunologically mediated renal damage. The antigen still is unidentified. Removing the antigenic challenge by stopping heroin injection apparently interdicts the progression of renal disease. Renal transplantation can be effectively accomplished in patients with HAN without early recurrence if patients discontinue the use of heroin.