The vitamin E-bonded polysulfone membrane hemodialyzer (ViE™-21) was evaluated in a clinical study for regulatory submission. Seventeen patients on hemodialysis were treated with conventional high-flux hemodialyzers for 2 weeks (Pre-ViE phase) and switched to the ViE-21 for 36 sessions (ViE phase) followed by an additional 2 weeks on conventional hemodialyzers (Post-ViE phase). Reduction ratios of urea, creatinine, beta-2-microglobulin, albumin, and ultrafiltration coefficients (KUF) were measured once during the Pre-ViE phase and twice during the ViE phase. Moreover, biocompatibility markers [leucocyte count, platelet count, and activated complement factor (C3a) levels] were evaluated pre-dialysis, 15 min after initiation, and post-dialysis. During the study, type and number of adverse events (AEs), and device malfunctions were recorded. ViE-21 reduction ratios and KUF were not noticeably different than those of conventional hemodialyzers. Fluctuations of leucocyte counts and C3a concentrations were similar using ViE-21 and conventional hemodialyzers; however, the platelet count fluctuation was lower in ViE-21 sessions. The frequency of episodes of hypotension occurring during the ViE phase was lower than that occurring during the Pre- and Post-ViE phases. In conclusion, this study provided performance and safety data of the ViE-21 for regulatory application. The data suggest that vitamin E-bonded hemodialyzers are beneficial in lowering platelet activation and frequency of intradialytic hypotension. Larger randomized controlled trials are needed to confirm these findings.