The project management success is the key motivator for the self-efficacy and it pushes them to work harder. If they failed to achieve business success even after long time period and effort, the entrepreneurial self-efficacy will be weakened and have little knowledge management processes and motivation to sustain the business. Therefore, the aim of this research is to contribute to the existing literature by identifying and examining the knowledge management processes influence on project management success via self-efficacy as mediating effect among SMEs in Yemen. The researcher introduced the topic of “The influence of knowledge management processes on project management success among SMEs in Yemen: The Mediating Role of Self-Efficacy”. The research also discusses the SMEs in Yemen economy, and the problems related to the study of project management success, the research questions, and the research objectives. Additionally, the research presents the significance and scope of the study as well as the definition of key terms. Moreover, the researcher discusses the conceptual framework and various pieces of literature that related topics regarding knowledge management processes and its impact on project management success through self-efficacy as mediating effect. In addition, the research indicates of the detailed methodology process to be carried out for the conduction of the re-search. In the section that provides insight the research method, sampling method and questionnaire design. Finally, the researcher explains the statistical test and data analysis procedure.