The purpose of this study was to determine the most ideal dialysate sodium concentration (DSC) for interdialytic weight gain (IDWG) and blood pressure in chronic hemodialysis patients. A retrospective, descriptive design was employed to investigate the relationship between the DSC and IDWG and blood pressure. Chart reviews were performed to collect data. A total of 221 clients receiving dialysis at three dialysis centers in central Taiwan were included in the study. These clients were grouped according to DSC into the low DSC group (≦low 138 mEq/L; n = 29) and high DSC group (≧139 mEq/L; n = 192). Independent t-test was used to determine the differences in IDWG and blood pressure between the groups. Significant difference in IDWG was found (t = 2.14, p = .03); patients receiving hemodialysis had less IDWG with a low DSC. However, there was no significant difference in pre-dialysis blood pressures for either systolic blood pressure, diastolic blood pressure, or mean arterial pressure. IDWG could be improved when DSC level was set at ≦138 mEq/L.