Introduction Risk stratification of patients with syncope with cardiac cause in the Emergency Department is an ongoing challenge and current risk assessment scores do not perform better than clinical judgement. The aim of this study was to develop a simple ECG based risk score to predict risk of death in patients presenting to the emergency department with syncope. Methods All patients >=18 years old presenting with syncope to the emergency department at a Danish hospital between October 21st, 2002, and December 31st, 2021, and an ECG recorded that same day were identified in the Danish Nationwide Electrocardiogram Cohort. A Cox proportional hazards model was developed to investigate the impact of ECG variables on mortality at 1, 3 and 5 years. The variables included in the model were age, sex, sinus rhythm, left bundle branch block, right bundle branch block, atrial fibrillation, ST elevation, ST depression, and 1. degree AV block. A nomogram was created to visualize the contributions of each variable, and the probability of mortality was calculated by summing the associated points. Results A total of 39,758 patients were included. We observed an increased risk of mortality with increasing age (HR = 1.09, 95% CI: 1.09-1.09), left bundle branch block (HR = 1.18, 95% CI: 1.05-1.34), right bundle branch block (HR = 1.13, 95% CI: 1.04-1.25), atrial fibrillation (HR = 1.30, 95% CI: 1.17-1.44), ST depression (HR = 1.42, 95% CI: 1.29-1.56), and non-sinus rhythm (HR = 1.18, 95% CI: 1.09-1.29). Conclusion The developed nomogram provides an easy method for clinicians to assess individual risk of mortality in patients with syncope with cardiac cause over multiple time points, hence aiding in personalized treatment planning and decision making.