The goal of the current research is to test the 15-items existential annihilation anxieties (EAA) scale cross-nationally. The EAA scale found in a previous study to have four first-order factors: psychic, collective, status and physical identity EAA, and a unitary second-order factor. The study utilized a previously collected data (N = 1566) that included five countries: Egypt (N = 490), Turkey (N = 420), Kuwait (N = 300), UK (N = 177) and Syria (N = 179). Participants included 51.4% of males and 14.6% of adolescents. Age ranges between 14 and 75. Measures included EAA, cumulative stressors and traumas (CST), the "will to exist, live and survive" (WTELS), the Rosenberg self-esteem scale, emotion regulation, identity salience, PTSD, and poor health. We conducted a zero-order correlation between the primary variables, alpha reliability, and confirmatory factor analysis of the factor structure of EAA, found in the previous study. We further tested its invariance across different age, gender, and national groups. Results indicated a high alpha of .92 of the scale. The confirmatory factor analysis found that the previously found structure fit well in the multinational data and was strictly invariant across genders and age group and strongly invariant across the five national groups. EAA highly correlated with PTSD (.52) and correlated with psychopathology, internalizing, externalizing, thought disorder, poor health, and CST. EAA was negatively correlated with WTELS, self-esteem, religiosity and emotion regulation (reappraisal). The EAA scale has robust psychometrics cross-nationally, and its conceptual framework is clinically significant and worth considering as a new focus of the new Transdiagnostic intervention strategy for PTSD.