Amyloidosis is an important cause of mortality and morbidity in patients with end-stage renal disease (ESRD) undergoing hemodialysis (HD). In this study, depending on the idea that the clearance of middle and high molecular weight toxins could be improved, we aimed to investigate the effect of high-flux dialyzer on clearance of beta-2 microglobulin (beta2-MG) and calcium (Ca) phosphorus (P) metabolism in patients under HD treatment. Forty-eight patients with ESRD under chronic HD treatment were included in the study. All patients were randomized into two groups, and HD was performed with low-flux or high-flux dialyzer for 6 months. In the high-flux group, the reduction of beta2-MG and P levels during dialysis was significantly higher when compared with the low-flux group (p<0.001). During the follow-up period, while beta2-MG levels decreased significantly in the high-flux group (p<0.05), there was an increase in the low-flux group (p<0.05). As a result, our findings suggest that use of high-flux dialyzer can be an efficient alternative in terms of controlling the clearance of beta2-MG and impaired Ca and P metabolism. These beneficial effects of high-flux dialyzers are probably mediated by the improved clearance of middle and high molecular weight toxins.