Although sleep problems are thought to be prevalent among patients who undergo dialysis, there is only limited information on the determinants of sleep quality and the change in sleep quality during the first year of dialysis treatment. This report uses data from a national cohort study of incident hemodialysis and peritoneal dialysis patients to identify the correlates of sleep quality and to determine the extent to which sleep quality is related to patients' health-related quality of life and survival. This report includes 909 incident dialysis patients who responded to questions about sleep quality. Three quarters of incident dialysis patients reported impaired sleep, and 14% had a decline in sleep quality in the first year of treatment. Poor sleep quality was significantly related to black race, higher serum phosphate, current smoking, benzodiazepine prescription, and complaints of severe restless legs. Poor baseline sleep quality was associated with lower SF-36 physical and mental component summary scores, vitality scores, and bodily pain scores (all P < 0.001). Younger age, current smoking, and benzodiazepine prescription were associated with decreases in sleep quality at 1 yr. There was no association between baseline sleep quality and survival; however, a decline in sleep quality during the first year on dialysis was associated with shorter survival (hazard ratio 1.44; 95% confidence interval 1.13 to 1.83; P = 0.003). Future work should examine the link between sleep quality and daytime functioning in the kidney failure population and the extent to which improving sleep quality will improve dialysis patient outcomes.