The question of whether hyperuricemia can induce chronic direct renal injury has been argued for many decades. Despite continued efforts and strong motivations to seek an answer, the current evidence still cannot definitively prove or refute the hypothesis. Recent data in rodents do favor causality between hyperuricemia and renal disease. Human epidemiologic data are quite varied, but positive studies do exist. Pathophysiologic models of biology for this entity are sparse in animals and nonexistent in humans.