This study evaluated the flow rate and composition of whole saliva in patients with chronic renal failure undergoing hemodialysis. In the group on dialysis (RG) (n = 15), saliva was collected just prior to hemodialysis CT1) and at completion (T2), while in the healthy subjects (HG)(n = 15) saliva was collected at the same time of day as the pre-dialysis. Saliva samples were analyzed by inductively coupled argon plasma with atomic emission spectrometry. Significant differences were found in the flow rate, potassium, magnesium and phosphorus concentrations at the RG-T1 and HG (p < 0.05). Sodium concentration at RG-T1 and RG-T2 were higher than HG (p < 0.05). Total protein concentration was higher at RG-T1 than at the other two analyses. Salivary peroxidase activity at RG-T1 and RG-T2 was lower than at HG. Our findings suggest that in patients with chronic renal failure, the saliva is altered. Hemodialysis, however, seems to help control saliva composition and flow rate.