mergency departments are places where seconds are critical for patients, and health professionals work under immense time pressure and patient volumes. 1,2 Providing effective and timely treatment for patients can mean the difference between life and death. One of the conditions of providing such treatment is determining which patient has priority for service. 3,4 A triage system to prioritize patients is the most suitable approach for patient safety. [3][4][5] It is difficult to make decisions under high patient intensity and diversity, in a complex and dynamic environment such as an emergency department triage. 6 Decision support systems (DSSs) can provide successful solutions to overcome these difficulties. 7,8 In the literature, it was reported that a DSS supports triage decisions, 9 helps overcome the challenges in emergency settings, 10,11 and increases consistency of triage decisions. 12 When we reviewed the literature, we observed that most of the triage assessment is carried out on paper, 10 increasing workload and hampering effective time management, and more importantly, opening the way for human error. 10 Human-made emergency department (ED) triage decisions suffer from the limitations of an individual's experience and ability. 13 Decision support systems in emergency services are effective in determining triage levels and making critical decisions, 10 and they can help nurses identify high-risk conditions. 11 Electronic triage systems provide analytical predictions to endorse triage decisions, 13 and their use should be encouraged. 14 Decision support systems can help triage nurses at all levels of experience by pointing out high-risk situations, 11 thereby improving patient safety. 15 Objective For these reasons, we developed a computer-based DSS for ED to determine triage levels objectively, reduce human error, and improve safety for patients and healthcare staff. We aimed to integrate the DSS into HIMS and evaluate the triage nurses' opinions. The system supports triage decisions with given measurable criteria, and it can be applied to any institution with a HIMS. HIMS is the abbreviation for the general name given to a group of software that is used to process all medical patient data. 16 We showed that their weaknesses could be eradicated using the Australasian Triage Scale (ATS) and Emergency Severity Index (ESI) algorithms.This study aimed to design and implement a DSS to assist nurses in the ED to make correct triage decisions, and reports triage nurses' user opinions on the DSS.