Background: Secondary traumatic stress known as compassion fatigue or vicarious trauma, is a psychological condition that affects nurses who are indirectly exposed to traumatic events or experiences through their work or close relationships with those directly affected. Aim of the study: To assess of knowledge and awareness of emergency nurses regarding secondary traumatic stress at emergency unit. The Research design: A descriptive research design was used in this research . Setting: This study subject was conducted in emergency department of at both El-Odessat Hospital and Assiut University. Sample: A convenience sample of all intensive care nurses working in the aforementioned settings, who provide direct care to critically ill patients, was included. The tools,: Two tools were utilized in this study. Tool I: Emergency nurses' assessment tool and Tool II: Secondary traumatic stress scale. Results: It was found that 56 % from nurses had satisfactory knowledge regarding secondary traumatic stress, 38 % from nurses had fair awareness while 28% from nurses had good level of awareness with mean & standard deviation 2.42±.966. Conclusion: Most critical care nurses exhibited satisfactory knowledge of secondary traumatic stress, with nearly 40% demonstrating fair awareness. There was no significant relationship between total knowledge and awareness scores. Recommendations: Enhancing education and training programs on secondary traumatic stress within nursing curricula and workplace settings is essential for improving awareness among emergency nurses.