Since the first report on the acquired immunodeficiency syndrome (AIDS) in 1981, organ involvement of AIDS has increased. We discuss the effect of human immunodeficiency virus (HIV) infection, the causative agent of AIDS, on the field of nephrology. Hyponatremia, the commonest fluid and electrolyte abnormality, is caused by various pathophysiologic mechanisms, including adrenal insufficiency. The renal parenchymal complications are diverse, but a new entity, HIV-associated nephropathy, is becoming recognized because of its characteristic clinical and pathologic features, including the fact that it causes irreversible renal failure. HIV infection in patients with end-stage renal failure, both before and after initiation of maintenance dialysis, is a significant problem. The present methods of preventing spread of virus in dialysis units seem successful. Few patients who are infected with HIV or who have AIDS have had renal transplantation, although unsuspected viral infection of cadaveric organs remains a concern.