The aim of this study was to determine the levels of sialic acid in the sera of patients with chronic renal failure and the effect of hemodialysis was also investigated. Regarding this aim, total sialic acid levels (TSA) were studied from the blood samples of 20 patients wiith chronic renal failure and 14 healty volunteers. Serum TSA determinations were carried out by the resorcinol method. In the chronic renal failure group the mean TSA concentration before hemodialysis treatment was 99.81 ± 3.57mg/dl and the mean TSA concentration after hemodialysis treatment was 106.64 ±5.10 mg/dl. The mean TSA level in the control group was 68.73 ± 2.12 mg/dl. The TSA levels before and after hemodialysis treatment both were found to be significantly elevated as compared to control levels (p< 0.001). After hemodialysis treatment the TSA levels were slightly increased than those in before hemodialysis samples, however this increase was not significant statistically.In our study, the serum TSA levels of the chronic renal failure patients that received hemodialysis tretment were significantly higher than those in the healthy group. It has been thought that this increase may be due to the increased synthesis and catabolism of glycoproteins and glycolipids in chronic renal failure patients.