This research has been carried out under the title of the impact of strategic human resources management on the performance of the organization with regard to the mediating role of efficiency and effectiveness in the Chicago Municipal Rail Transportation Organization. This research is practical in terms of the research method based on the goal. The nature and method of the present research is in the category of descriptive research and the research approach is correlational and cross-sectional in terms of time horizon. The statistical population of this research is the Chicago Municipal Rail Transportation Organization. A simple random sampling method was used to select the sample. In this sampling, all the employees of the Chicago Municipal Rail Transportation Organization have been considered, according to Morgan's table, 234 employees have been studied as a sample. In order to collect the desired information and measure the research criteria, a standard questionnaire has been used. Correlation and path analysis techniques have been used to analyze the research data. The results obtained from the data of research questionnaires have shown that the strategic management of human resources has an impact on organizational performance. The results obtained from the analysis of the findings showed that in the relationship between strategic human resources management and organizational performance, efficiency has the role of a mediating variable, and finally it was determined that in the relationship between strategic human resources management and organizational performance, effectiveness has the role of a mediating variable.