Introduction: Previous studies have indicated that educationally influential physicians' (EIPs) interactions with peers can lead to practice changes and improved patient outcomes. However, multiple approaches have been used to identify and investigate EIPs' informal or formal influence on practice, which creates study outcomes that are difficult to compare. The purposes of this systematic literature review were to (1) compare approaches used to identify EIPs and (2) identify and compare shared characteristics of EIPs as defined by the included studies. Methods: Articles in English were obtained from PubMed, CINAHL Plus, ERIC, PsycINFO, Web of Science, Google Scholar databases, and reference lists of identified articles. Studies were compared and contrasted based on terminology, identification approach, selection criteria, and EIP characteristics according to Cresswell's 5 steps in conducting a literature review. Results: Thirty-one studies met the inclusion criteria. Sociometric questionnaires and peer informants were used most frequently to identify EIPs. Multiple and varied criteria, including physician ranking, nomination by peers, percentage of nominations received, and number of votes were used by researchers to select physicians who were classified as EIPs. The identified characteristics of EIPs varied by study, with some researchers adhering to characteristics previously described by Hiss, and others adding to or deviating from those characteristics, at times based on physician specialty. Conclusion: Selection of an EIP identification approach requires agreement on EIPs' characteristics, consistent approaches and identification criteria, and common terms and definitions. Additional research is needed to compare characteristics of EIPs and study outcomes based on the identification method employed. (Contains 5 tables and 1 figure.)