Sleep disorders for patients on dialysis are significant causes of a poorer quality of life and increased morbidity and mortality. No study has evaluated patients undergoing automated peritoneal dialysis (APD) to assess their sleep disorders compared to hemodialysis (HD) and continuous ambulatory peritoneal dialysis (CAPD). A total of 166 clinically stable patients who had been on dialysis for at least 3 months were randomly selected for the study and divided into HD, CAPD or APD. Socio-demographic, clinical and laboratory parameters and self-administered questionnaires were collected for the investigation of insomnia, restless legs syndrome (RLS), bruxism, rapid eye movement sleep behavior disorder, excessive daytime sleepiness (EDS), obstructive sleep apnea syndrome (OSAS), sleepwalking, sleep hygiene, depression and anxiety. Insomnia was detected in more than 80 % of patients on the three modalities. OSAS was lower for patients on HD (36 %) than on CAPD (65 %) (p < 0.01) or APD (60 %) (p < 0.04). Patients on APD were more likely to have RLS compared to those on HD or CAPD (p < 0.04) (50 vs. 23 vs. 33 %). No differences among the modalities were found in bruxism, EDS, sleepwalking, sleep hygiene, depression or anxiety. ESRD patients undergoing any one of the three dialysis modalities studied had a high prevalence of sleep disorders. Patients on HD had a lower proportion of OSAS than those on CAPD and APD, which is most likely attributed to their lower body mass indices. The possible causes of higher RLS rates in APD patients have not been established.