Background: The (COVID-19) pandemic created a remarkable impact on healthcare providers both physically and psychologically. Perceived psychological stress (PSS) influences the homeostatic equilibrium, involving activation of the sympathetic nervous system and hypothalamus pituitary adrenal (HPA) axis. Copeptin; C-terminal portion of Vasopressin (AVP) precursor is stable, however, evidence about impact of PSS on copeptin levels is limited. Aim: Of this study was to estimate the influence of psychological stress on copeptin levels among healthcare providers working in intensive care unit (ICU). Methods: A total of 70 healthcare providers (HCP) served in quarantine ICU participated in this prospective study; 35 physicians (28 males and 7 females) and 35 nurses (10 males and 25 females). A control group of 40 HCP matched age, BMI and specialty in non-quarantine hospitals. Fasting morning blood samples were withdrawn for determination of copeptin, cortisol, insulin at three points; first point was pre-quarantine at ICU. Second point at end of first week in quarantine and third point was two weeks’ post quarantine. A questionnaire was conducted to all participants to assess stress (PSS). Cortisol was determined by a chemiluminescence immunoassay while insulin and Copeptin were measured by ELISA. Results: Baseline plasma copeptin level pre-quarantine was significantly increased 15.76±8.6 pmol/l (P= 0.001*) and was positively correlated with high stress PSS score mean 66.9± 18.3. Post-quarantine copeptin was markedly reduced 3.98±1.28 pmol/l and mean PSS was 23.0±7.95(P= 0.001*). Also, there was positive correlation between plasma copeptin and PSS, systolic blood pressure and serum insulin. On the other hand, there was no correlation between copeptin and serum cortisol. Conclusion: Our finding suggested that copeptin may be used a potential biomarker for physiological strain during work in a stressful environment.