Objective: We retrospectively analyzed blood pressure metrics obtained during serial dialysis sessions over a 90-day period from a single dialysis center from 2016 to 2017. The mean values and the frequency of specific values of blood pressure were analyzed as predictors of 3-year mortality. Methods: A total of 430 patients who underwent maintenance dialysis were included. The mean age was 63.3 ± 12.4 years and 58.6% were male. A low minimum systolic blood pressure (min SBP) <110 mmHg during dialysis was significantly associated with increased all-cause mortality. The frequency of min SBP <100 mmHg was the most significant predictor of 3-year mortality with an area under the curve (AUC) of 0.722. Furthermore, the frequency of min SBP <100 mmHg significantly increased the predictability of mortality when combined with the presence of other clinical factors (AUC: 0.786 vs. 0.835, p=0.005). Results: Among the various intradialytic blood pressure metrics, the frequency of min SBP <100 mmHg is the most significant factor related to all-cause mortality. The guidelines for the management of blood pressure in dialysis patients should consider including min SBP <100 mmHg as a definition for IDH. Conclusions: Objective: Intradialytic hypotension (IDH) has been reported to be an important prognostic factor in hemodialysis patients. However, a standard definition of IDH has not yet been determined. Methods: We retrospectively analyzed blood pressure metrics obtained during serial dialysis sessions over a 90-day period from a single dialysis center from 2016 to 2017. The mean values and the frequency of specific values of blood pressure were analyzed as predictors of 3-year mortality. Results: A total of 430 patients who underwent maintenance dialysis were included. The mean age was 63.3 ± 12.4 years and 58.6% were male. A low minimum systolic blood pressure (min SBP) <110 mmHg during dialysis was significantly associated with increased all-cause mortality. The frequency of min SBP <100 mmHg was the most significant predictor of 3-year mortality with an area under the curve (AUC) of 0.722. Furthermore, the frequency of min SBP <100 mmHg significantly increased the predictability of mortality when combined with the presence of other clinical factors (AUC: 0.786 vs. 0.835, p=0.005). Conclusions: Among the various intradialytic blood pressure metrics, the frequency of min SBP <100 mmHg is the most significant factor related to all-cause mortality. The guidelines for the management of blood pressure in dialysis patients should consider including min SBP <100 mmHg as a definition for IDH.