Peritoneal dialysis (PD) and hemodialysis (HD) are both common forms of dialysis for patients with end-stage renal disease. A few case reports have suggested that cough is associated with PD. From 1991 to 1998, 17 patients being treated with PD at the Toronto Western Hospital demonstrated persistent cough severe enough for referral to a respirologist. Causes of cough, often more than one cause per patient, included asthma, post-nasal drip, gastroesophageal reflux disease (GERD), chronic obstructive pulmonary disease, congestive heart failure, allergic rhinitis, pleural effusion, and respiratory infection. The aim of this cross-sectional study was to establish the prevalence of cough among PD patients, to determine if PD patients more commonly have a dry persistent cough than do HD patients, and, if the latter case is true, the possible reasons for it. A detailed survey of 92 PD patients and 91 HD patients was conducted in 1998 and 1999 at the University Health Network. Survey questions inquired about patient respiratory symptoms since onset of dialysis. Charts were reviewed to obtain information on use of medications possibly relevant to cough. In the PD and HD groups, 52% and 23% were females (p = 0.001), and the mean ages were 59.1 and 60.1 years, respectively. Angiotensin converting enzyme (ACE) inhibitors had been taken by 65% (PD) and 55% (HD) of patients, and beta-blocking medications by 43% (PD) and 51% (HD). Since initiation of dialysis--mean 2.7 years (PD) and 3.7 years (HD)--22% of PD patients reported persistent cough versus 7% of HD patients (p = 0.003). Although no significant association was seen between cough and self-reported heartburn in HD patients (p = 0.439), a significant association between cough and self-reported heartburn was seen in PD patients: 67% of PD patients with persistent cough reported heartburn versus 29% of those without cough (p = 0.008). The findings suggest that GERD and associated cough are more common in PD patients than in HD patients, perhaps owing to increases in intra-abdominal pressure from the peritoneal dialysate.