Many patients with end stage renal disease (ESRD) undergoing dialysis therapy suffer from sleep disturbances. The aim of this study was to investigate the prevalence of sleep disorders in a large population of uraemic patients recruited from 20 different dialytic centres in Triveneto. 883 patients on maintenance dialysis were enrolled in the study. Demographic, lifestyle, renal and dialysis data were recorded. Renal parameters were compared with the database of the Veneto Dialysis Register. Using a self-administered questionnaire we assessed the presence of the following sleep disorders: insomnia, restless leg syndrome (RLS), obstructive sleep apnoea syndrome (OSAS), excessive daytime sleepiness (EDS), possible narcolepsy, sleepwalking, nightmares and possible rapid eye movement behaviour disorders (RBD). Moreover, in order to determine the prevalence of sleep disturbances and the possible effect of demographic or clinical data on sleep, we divided our population into two groups: with (SLEEP+) and without (SLEEP-) sleep disorders. The questionnaire revealed the presence of insomnia (69.1%), RLS (18.4%), OSAS (23.6%), EDS (11.8%), possible narcolepsy (1.4%), sleepwalking (2.1%), nightmares (13.3%) and possible RBD (2.3%). Eighty percent demonstrated SLEEP+, having at least one sleep disorder. Independent risk factors for sleep disorders were advanced age (P<0.001), excessive alcohol intake (P<0.04), cigarette smoking (P<0.006), polyneuropathy (P<0.05) and dialysis shift in the morning (P<0.001). The questionnaire showed a high presence of sleep disruption in dialytic populations. Awareness by Italian nephrologists regarding sleep disruption seems to be insufficient. Our data might help nephrologists to deal with uraemic patients with possible sleep disorders. Concerning the high prevalence of possible narcolepsy, further studies using polysomnographic records are necessary to confirm our results.