Background: Emergency nurses face many stress factors at the same time, which can cause physical and mental fatigue in these nurses. The eye movement desensitization and reprocessing (EMDR) technique is a valuable psychotherapy approach to stem the psychological and emotional consequences of these stress factors. The aim of this study was to evaluate the effect of eye movement desensitization and reprocessing technique on anxiety and post-traumatic stress symptoms among emergency nurses. This study was carried out using a quasi-experimental design at the Emergency Departments of Accidents Hospital, Obstetrics and Gynecology Hospital, and Pediatrics Hospital at Zagazig University Hospitals, Sharkia Governorate, Egypt. The study included a sample of seventy-five emergency nurses who met the inclusion criteria. The study’s data were collected using the following tools: a structured interview questionnaire composed of two parts (a demographic data sheet and a work data sheet), the Beck Anxiety Inventory (BAI), and the Post-Traumatic Stress Disorder Checklist for the DSM-5 (PCL-5). Results: The findings of this study showed highly significant improvement (p < 0.0001) in levels and mean scores of anxiety as well as post-traumatic stress symptoms after implementation of the EMDR technique compared with before implementation of the EMDR technique. Conclusions: Eye movement desensitization and reprocessing technique was effective in reducing anxiety and post-traumatic stress symptoms among emergency nurses. Therefore, it is recommended that emergency nurses use the EMDR technique as a non-pharmacological method for decreasing anxiety and post-traumatic stress symptoms.