Fifteen unselected end-stage renal disease patients (nine hemodialysis [HD] and six continuous ambulatory peritoneal dialysis [CAPD]) were randomly selected from four Sydney metropolitan dialysis centers for sleep assessment by full polysomnography. Four of six CAPD patients and eight of nine HD patients were found to have clinically significant obstructive sleep apnea. An additional 21 unselected patients (10 CAPD and 11 HD patients) were assessed using overnight home monitoring of nasal airflow and arterial oxygen saturation. Of these, 8 of the 11 HD and 7 of the 10 CAPD patients were found to have obstructive sleep apnea. These data confirm the high incidence of obstructive sleep apnea in the end-stage renal disease population at large. Screening for obstructive sleep apnea should become a routine part of the management of these patients.