E-learning is a method that meets the time and distance needs of postgraduate medical education. The general workload of postgraduates and disasters such as the COVID-19 pandemic create a need for e-learning. Therefore, in recent years, e-learning has drawn the attention of researchers because of its potential as a practical instructional approach in PGME. Systematic review method was employed in this study aiming to examine the e-learning applications in PGME through a summary of several recent studies that meet predetermined criteria regarding e-learning for postgraduate medical education. The PICOS (population, intervention, comparison, outcome, study design) framework was used to decide on inclusion and exclusion criteria. On reporting the results of the study, The Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) was used. The review examines the differences between the identified studies in terms of research methods, data collection tools, study duration, sample size, and data analysis method. In addition, it compares the learning technology used, the format of e-learning delivery, types of e-learning, e-learning delivery features, learning content, content type, knowledge type, and learning outcome components of the studies. 57 studies that matched the desired quality indicators were identified from 10 databases. The majority of the studies worked on knowledge, attitude, and satisfaction. The studies were based on various methodologies and were carried out in a wide range of subject areas. There is a need to conduct more studies to compare different methods, tools, and pedagogical approaches in future studies.