Introduction: Knowledge management is one of the most interesting and challenging topics in management science in the new millennium. Public Library Institutions is one of the most talented organizations to implement knowledge management programs with libraries and information centers that have an educational and research environment. The purpose of this study is to identify and rank the factors affecting the establishment of knowledge management and assess the maturity and readiness of public libraries in the country and provide a model for the establishment of knowledge management in libraries. Methodology: The present study is a mixed approach. It used the hybrid method to identify the factors affecting the establishment of knowledge management in Public Library Institutions and the TOPSIS technique to prioritize effective factors, to assess the status of knowledge management maturity in public libraries from the Asian productivity maturity model and to design a model for establishing knowledge management in libraries. Interpretive structural modeling (ISM) was used in Iran and structural equation modeling (ESM) was used to confirm the general research model. The statistical population of this study is managers, administrative staff, mayors and officials working in public libraries of the country and the sample includes 21 experts (in terms of education 4 bachelors, 12 masters, 5 doctors who had 7 to 18 years of experience in public libraries) and were selected by cluster sampling. Data collection tools including library studies, semi-structured interviews, questionnaire (Knowledge Management Indicators Prioritization Questionnaire with Cronbach's alpha (0.713), Knowledge Management Maturity Assessment Questionnaire with Cronbach's alpha (0.9), Questionnaire (ISM): For the effect of each index on other indices with Cronbach's alpha (0.782) and in the structural equation questionnaire which is to design a pattern of complex and multiple relationships between indices with Cronbach's alpha (0.832)). Data analysis was performed using Excel software, TOPSIS software, and structural equation model software (PLS). Findings: The meta-synthesized results led to the identification of 107 codes, 15 indicators and 4 main dimensions in the establishment of knowledge management. According to experts and using the Delphi method, their localization and screening was done. In the next phase, the maturity status of knowledge management of Public Library Institutions in the country was measured by the Asian productivity maturity model. After the research steps, with the interpretive structural modeling method, the leveling of knowledge management establishment indicators was done and the conceptual model was validated using the structural equation modeling method. Conclusion: The results showed that technology has the greatest impact and organizational culture has the least impact on the establishment of knowledge management in Public Library Institutions in the country. Assessing the maturity status of knowledge management institution with Asian productivity maturity model with a score of 109 was in the beginning stage. Finally, the pattern of knowledge management deployment was drawn at 6 levels, of which information technology index (C3) and information systems index (C1) have the most influential level and indicators of information acquisition processes (C7) and knowledge transfer processes (C3) are with the most influential level. Finally, research suggestions were presented based on the results of reviewing the current status of the organization under study.