We read with great interest the nice article by Etemadi and colleagues, in your journal, Revista Portuguesa de Pneumologia, entitled “Unexplained pulmonary hypertension in peritoneal dialysis and hemodialysis patients”.1 In a retrospective study of chronic hemodialysis and peritoneal dialysis patients, pulmonary hypertension was found in 14 (41.1%) patients of the hemodialysis group and in 6 (18.7%) patients of the peritoneal dialysis group, where pulmonary hypertension was defined as a systolic pulmonary artery pressure (SPAP)≥35mmHg. They concluded that unexplained pulmonary hypertension seems to be more frequent in patients undergoing hemodialysis than with patients in the peritoneal dialysis group. In this context, I would like to make a few points about pulmonary hypertension in dialysis patients. In a study of 102 maintenance hemodialysis patients, we found pulmonary artery pressure of 41.5±12.6mmHg. In our study, 76.5% of hemodialysis patients had SPAP=35mmHg. In this study we can also see that pulmonary artery pressure had significant positive correlation with the duration and degree of hemodialysis.2 In another study we also observed that pulmonary artery pressure had significant positive correlation with serum intact parathormone.3 Pulmonary arterial hypertension is a serious cardiac complication among patients with end-stage kidney disease, especially patients on hemodialysis as mentioned in the study by Etemadi et al., and we need to look for other aggravating factors among dialysis patients.3–5 In order to achieve better understanding about this aspect of dialysis patients, more clinical studies are suggested.