Background and Aim: To optimize emergency services depend s on appropriate management structures and efficient and effective information system design . This study aim ed to investigate emergency department staff's information needs of emergency information system and to design a conceptual model of these needs.

 Materials and Methods: This descriptive study was performed among nurses and emergency medicine professionals working in emergency units of 9 hospitals affiliated to Tehran and Shahid Beheshti U niversities of M edical S ciences . Data w ere collected by interviewing 25 staff members in the emergency department , model d esign by RUP method and UML language and questionnaire d istribution among 315 staff members in the emergency department. Data collected were analyzed by descriptive statistics and SPSS.

 Results: Most nurses and emergency medicine physicians believed that multiple data elements such as time of patient’s first visit and procedure , t he latest status of patient, medical procedure taken , and paraclinical procedure taken must exist in the emergency information system . Also 68.3% (108) of them agreed with the relationship between data elements required in the clinical practice process .

 Conclusion : It is concluded that the presence of identity , clinical , and paraclinical data in emergency information systems can produce an electronic medical record. According to these data, elements can improve the coordination between the hospital emergency and pre- hospital rescue teams , controlling of victim status , access to patient reports and quality of service to patients.