AIM: Assess the levels of psychological flexibility, burnout, and turnover intention among critical care nurses and assess the impact of psychological flexibility on burnout, and turnover intention among critical care nurses. BACKGROUND: Burnout and turnover intentions among critical care nurses are rapidly increasing because of the challenges of COVID-19. There is a need for evidence-based interventions like psychological flexibility to be addressed in research to overcome those challenges. METHODS: A descriptive correlational research. A convenient sample of 200 critical care nurses working in COVID-19 hospitals from two governorates in Egypt. The sociodemographic and clinical data sheet, the work-related acceptance and action questionnaire, the Copenhagen burnout inventory, and the adopted version of the staff nurses' intention to leave the nursing profession questionnaire were used. RESULTS: The majority of critical care nurses reported a moderate level of psychological flexibility (75.5%, Mean = 31.23), a moderate level of burnout (65.5%, Mean = 59.61), and low to moderate levels of intention to leave (73%, Mean = 5.95). Psychological flexibility has a statistically significant negative correlation with burnout (PC = -0.304, Sig = 0.000) and the intention to leave (PC = -0.258, Sig = 0.000). In addition, psychological flexibility has a predictable effect on decreasing burnout (R = 0.232) and intention to leave (R = 0.127) among critical care nurses. CONCLUSION: critical care nurses in COVID-19 hospitals reported varied levels of burnout and an intention to leave that must be considered. The effect of psychological flexibility on burnout and intention to turnover highlighted the importance of improving it among critical care nurses by applying acceptance and commitment therapy as a management intervention.