The aim of this study was to reveal the pulmonary function status of renal transplant recipients and chronic renal failure patients on hemodialysis or continuous ambulatory peritoneal dialysis. The study involved 73 subjects, including 49 patients who were either on peritoneal dialysis (n = 22) or hemodialysis (n = 27), and 24 renal transplant recipients. The spirometry results revealed significantly higher residual volume and total lung capacity in the hemodialysis and peritoneal dialysis groups than in the transplantation group. Forced expiratory flow between 25% and 75% of vital capacity was slightly below normal in the dialysis patients. Preservation of diffusion capacity of the lung for carbon monoxide was noted in the hemodialysis group (112.4%). Inspiratory and expiratory muscle strength was reduced in all groups. Only type of dialysis was correlated with this reduction. Inspiratory muscle strength in the peritoneal dialysis group (49.9%) was significantly lower than in the transplantation and hemodialysis groups (54.7% and 66.5%, respectively). The spirometry findings suggest that small-airway disease causes increased residual volume and total lung capacity (hyperinflation) in hemodialysis and peritoneal dialysis patients and that this airway obstruction subsides after renal transplantation. Preserved diffusion capacity in the hemodialysis group was attributed to the use of biocompatible dialyzer membranes. Renal failure complications may be the main explanation for global respiratory muscle weakness in dialysis patients, whereas corticosteroid therapy might be the primary cause in kidney graft recipients. Significantly lower inspiratory muscle strength in the peritoneal dialysis group suggests that presence of intra-abdominal dialysate might interfere with diaphragmatic contraction.