The quality of project management activities plays an undeniable role in the success or failure of projects. Especially in project-based organizations with large projects, this success or failure is vital. One of the suitable tools to ensure the accuracy and quality of project management activities is continuous evaluation of the way these activities are performed, which is called "project management maturity level" evaluation. The aim of this study was to identify the dimensions of organizational maturity measurement of project management using the best-worst method in the municipality of District 3 of Tehran. The statistical population of this study is managers and experts of Tehran Municipality. The total number of senior managers is 30. Due to the limited society, sampling method is all number of experts in surveying and filling out questionnaires. At first, the dimensions of project manager maturity measurement were identified in six dimensions: financial, stakeholders, internal processes, growth of learning, employee satisfaction, environment and society. Then, the questionnaires of pair comparisons among 30 experts of distribution and the results of dimension analysis showed that after employees' satisfaction, first rank and dimensions of environment and society, growth and learning, internal processes, stakeholders and financial ranks second to sixth. Also, 23 indicators were identified in six dimensions. The results of this study can provide a comprehensive view to experts about identifying dimensions and measuring organizational maturity of project management of Tehran Municipality District 3.