Introduction: There are published criteria for identifying educational influentials (EIs). These criteria are based on studies that have been performed in developed countries. This study was performed to identify criteria and characteristics of EIs in Iran. Methods: The study was conducted on residents, interns, and clerks at a major educational hospital in Iran. This study had 3 stages: (1) preparation of an inclusive list of EI characteristics through 3 focus group discussions with 22 individuals, in which 30 primary characteristics of EIs were found; (2) reducing the number of characteristics by examining 154 individuals for exploratory factor analysis and internal consistency evaluation by Cronbach's alpha, after which the characteristics were reduced to 25; (3) finalizing the criteria through discriminant validity. Results: Fifteen characteristics were identified in 4 domains: (1) knowledge (high level of clinical knowledge, being up-to-date and an expert, high level of clinical skills); (2) communication skills (good communication with others, easily accessible, good public relations, and oratory); (3) taking into account the stakeholders (involving patients in decision making, allowing students to identify problems, delivering decisions to others, and interest in transfer of material); and (4) professional ethics (pursuing the patients' maximum benefit, observing ethics in education and research). Overall, they have a sensitivity and specificity of 87% and 74%, respectively. Discussion: Three of the four domains we found were already identified in other studies; however, the "taking into account the stakeholders" domain has not been previously reported. The other domains and criteria were similar to those found in developed countries. (Contains 3 tables.)