A newly developed questionnaire was administered to 140 hemodialyzed patients (82 M and 58 F) who have achieved adequate anemia correction according to the best guidelines with the aim: to evaluate the prevalence of clinical/subclinical dyssomnias in these patients; to study the influence of the dialytic shift (morning versus afternoon schedules) on sleep duration and disturbancies; and to evaluate the relationship between clinical sleep disorders and blood pressure values in uremic patients. Results indicated that 85% of uremic patients undergoing hemodialysis complain of clinical insomnia (frequent, persistent and associated with daytime consequences) or sub-clinical sleep disorders; patients dialyzing in the morning sleep significantly less during the night preceding the treatment, than those dialyzing in the afternoon; older patients complaining of clinical insomnia have a higher risk of failure to achieve target-optimal values in systolic blood pressure.