This article briefly summarizes the literature regarding possible defects in cell-mediated immunity in the setting of chronic renal failure. It is difficult to precisely determine the proximate cause or level of such defects from most studies. Confounding variables include reports on mixed patient populations (predialytic chronic renal failure, hemodialysis patients, and peritoneal dialysis patients) and studies before and after the introduction of erythropoietin for end-stage renal disease patients. While it seems clear that lymphopenia, suboptimal responses to mitogens, abnormal cytokine gene expression, and abnormal IL-2R expression are seen in a number of dialysis patients, the role of uremia versus dialysis in producing these abnormalities is unclear. In addition, it is difficult to determine whether T cell abnormalities are primary or secondary to impaired function of other interacting immune cells, such as macrophages. Clinical implications of defects in cell-mediated immunity are additionally discussed.