Introduction: Today, the secret of the success of any organization is the knowledge management. Because knowledge is such, it should only be done by oneself individually. So, this causes raising different psychological concepts in knowledge management. Given the undeniable role of individuals in today's business excellence, personal knowledge management topics vs. organizational knowledge management topics are discussed. The aim of this study was to investigate the moderating role of personal knowledge management on the impact of psychological characteristics on organizational competencies in information and knowledge services. Methodology: This is an applied study with a mixed method. The sample in qualitative section consisted of ones with research experiences in the field of personal knowledge management, and in the quantitative section, the staff of central libraries of Tehran’ s state universities. For this purpose, a researcher-made questionnaire with the seven dimensions of retrieving, evaluating, organizing, collaborating, analyzing, providing, and securing information was used for studying personal knowledge management, and the Neo questionnaire was used for the study of psychological characteristics, and a researchermade questionnaire was used with the five dimensions of external information awareness, internal knowledge dissemination, effective decision architecture, organizational focus, and continue innovation for measuring organizational competencies. The reliability of the questionnaire has been evaluated by Cronbach’ s Alpha, which was equal to. 728. Data was analyzed by the descriptive and inferential statistics methods. Findings: The results showed that the psychological characteristics have a direct effect on personal knowledge management and personal knowledge management has a direct effect on organizational competencies. The impact of psychological characteristics on organizational competencies was not confirmed, and the role of personal knowledge management was detected as a mediator. Conclusion: According to the results, in evaluating the personal knowledge of library staff, special attention should be paid on their personalities. To achieve the desired organizational competencies, the skills of library staff should be strengthen for their personal knowledge management.