To ensure the confidentiality of data and information, the Electronic Procurement Service Center (LPSE) of the Ministry of Finance of the Republic of Indonesia implements an Information Security Management System (ISMS) in accordance with ISO / IEC 27001: 2013 standards that focuses on information security. In its implementation, there were found many factors that could hinder the implementation of ISO / IEC 27001. From the results of literature review and interviews with the experts from the Indonesian Ministry of Finance's LPSE, there were at least 10 factors that could hinder the implementation of ISO / IEC 27001. Furthermore, the ten factors will be modeled in the form of causal diagrams and analyzed for their relevance using the DEMATEL method. The result shows that the lack of understanding of security standards is the most important inhibiting factor for the implementation of ISO / IEC 27001 without ignoring the factor of "lack of support from top management"and the "difficulty identifying organizational assets"as the most crucial causative factors for the implementation of ISO / IEC 27001.