Background: Cardiac arrest is a problem that has gotten surprisingly little attention in the ER. ER Patients are more likely (29%) than patients in the intensive care unit (25%) or on telemetry (25%), to encounter an initial ventricular fibrillation rhythm or pulseless ventricular tachycardia. Our research aims to identify the prognostic factors for cardiac arrest in the ER at KSMC. Method: From January 2022 to Jun 2022, a retrospective study was done in the tertiary care hospital KSMC in Riyadh, Saudi Arabia. The ministry of health introduced and oversees the hospital records system, which was used to collect data, in 2015. All persons over the age of 18 who experienced an in-hospital resuscitation attempt after cardiac arrest were eligible to take part in the study. Results: We included 98 people who received resuscitation techniques after suffering ER cardiac arrest. Patients who had ER cardiac arrest had an average age of 69.5 + 23.4 years. Overall, 60.2% of the patients were men. The two most common concurrent comorbidities were hypertension (43.8%) and coronary artery disorders (41.8%). The average time spent performing CPR was 22 minutes (IQR 11-49 minutes). When the factors influencing the success of resuscitation were determined using multiple regression analysis, resuscitation lasting fewer than 30 minutes was the most component that could predict the restoration of spontaneous circulation. Conclusion:Our study concluded that ER cardiac arrest more common in male gender. About one third of patients affected with ER cardiac arrest discharged home well.