AbstractThe kidney is a frequent target organ for toxic effects of xenobiotics. In recent years, the molecular mechanisms responsible for the selective renal toxicity of many nephrotoxic xenobiotics have been elucidated. Accumulation by renal transport mechanisms, and thus aspects of renal physiology, plays an important role in the renal toxicity of some antibiotics, metals, and agents binding to low molecular weight proteins such asα2u-globulin. The accumulation by active transport of metabolites formed in other organs is involved in the kidney-specific toxicity of certain polyhaloalkanes, polyhaloalkenes, hydroquinones, and aminophenols. Other xenobiotics are selectively metabolized to reactive electrophiles by enzymes expressed in the kidney. This review summarizes the present knowledge on the mechanistic basis of target organ selectivity of these compounds.