Sleep apnea is a surprisingly common disorder in end-stage renal disease (ESRD) and chronic renal failure. The symptoms of sleep apnea frequently go unreported or may be misdiagnosed as uremia, depression, chronic illness, or insomnia. A review of the literature was performed to define the prevalence, morbidity, and treatment of sleep apnea syndrome in the ESRD patient. Sleep apnea occurs in at least 60% of ESRD patients. The known complications of sleep apnea include arrhythmias, pulmonary hypertension, and systemic hypertension. In addition, sleep apnea has been implicated in coronary artery disease and strokes. The contribution of sleep apnea to the high mortality from cardiac disease and stroke in peritoneal dialysis and hemodialysis patients is unknown. The causes of the increased prevalence of sleep apnea in ESRD patients are unknown and likely differ from the general population, but the treatment is similar. The literature suggests that modality of renal replacement therapy does not matter; however, large nocturnal volume peritoneal dialysis may worsen sleep apnea. Renal transplantation may be curative. In conclusion, sleep apnea may be an under-diagnosed disease in patients on dialysis. There are significant reasons to suspect that sleep apnea may worsen the morbidity and mortality of ESRD, and there are potential successful therapies.