Background: Death anxiety and its consequence are among the most important mental health issues that should be considered in hypertension patients. Some studies reported that cognitive emotion regulation strategies, cognitive flexibility, and distress tolerance, both influence and predict mental health. Objectives: This study aimed to investigate the role of these variables on death anxiety among women with hypertension. Methods: This is a descriptive correlational study that was conducted on 150 women with hypertension who were referred to hospitals in Rasht in 2018. Participants were selected using the convenience sampling method. Death Anxiety scale (DAS), the Distress Tolerance scale (DTS), the cognitive flexibility inventory (CFI), and the short version of the Cognitive Emotion Regulation questionnaire (CERQ) were used to collect the data. Data were analyzed using both descriptive (means and standard deviations) and inferential (the Pearson correlation coefficient and stepwise regression analysis) analyzes using SPSS. Results: Overall cognitive emotion regulation strategies (r = -0.20), refocus on planning (r = -0.28), acceptance (r = -0.35), positive reappraisal (r = -0.20), and putting into perspective (r = -0.42) had diverse significant relationships with death anxiety. In contrast, catastrophizing (r = 0.19), rumination (r = 0.19), and self-blame (r = 0.16) had direct significant correlations. Besides, overall cognitive flexibility (r = 0.61), controllability (r = -0.21), alternatives (r = -0.44), behavioral justification (r = -0.23), overall distress tolerance (r = -0.21), tolerance (r = -0.18), appraisal (r = -0.15), and regulation (r = -0.17) had diverse significant correlations with death anxiety; however, absorption (r = 0.52) had a direct significant relationship with death (P ≤ 0.05). The results of the stepwise regression analysis indicated that the research variables were could explain 71% of the variance in death anxiety (R2 = 0.71), and overall cognitive flexibility had the strongest role in explaining death anxiety (beta = -0.67), which was significant at the 1% level (P ≤ 0.0001). Conclusions: Based on the findings, cognitive emotion regulation strategies, cognitive flexibility, and distress tolerance were associated with death anxiety, and cognitive flexibility had the strongest role in predicting death anxiety.