Since the first reports in the late 1960s and early 1970s there have been numerous studies describing the clinical and pathological features of renal diseases associated with chronic parenteral abuse of heroin, cocaine, morphine, amphetamine, and other narcotic and hallucinogenic drugs, including several adulterants. The past 35 years have witnessed an explosive growth in illicit drug use in many parts of the world. Meanwhile, drug addict nephropathy constitutes an important cause of end-stage renal disease. The term heroin-associated nephropathy' includes different morphological findings following chronic drug abuse. Up to now it still remains ambiguous as to whether or not heroin/morphine itself, adulterants, other diseases like hepatitis B and C infection, or HIV, lead to a spectrum of morphologically described heroin-associated' findings in the kidneys. As a measure of prevention it appears that the purity of heroin plays an important role.