Background: Several countries have established registries of clinical trials for intractable diseases to disseminate information. These registries are compared to glean their best features and learn from their drawbacks in order to create a patient-centered portal site for the Japan Primary Registries Network (JPRN). Method: We reviewed information available through 17 registries. The contents and types of information available from these countries registries accessed via the International Clinical Trials Registry Platform were summarized and compared. The findings guided the redesign of the new JPRN portal site. Results: Nearly all registry websites provide basic features. The majority of registries were created with a focus on providing information of value to registered users (i.e., medical personnel and researchers) through “FAQs” and “Help” pages. The study identified the information needs and problems related to existing registries. The study restructured the common contents of the standard registry, improving the search function, website structure, and convenience, to create a new portal site. The new portal website for patients provides reliable information on drugs and diseases, whereas that for healthcare providers provides a detailed search of clinical trials. Conclusion: The new site of clinical trial information of JPRN is a patient-centered portal site widely supporting patient’s medical treatment living in order to provide information on “Commentary on diseases”, “Common medicine”, “Status of clinical trials overseas” and “Overseas medicine” for each disease in addition to “Search methods”, “Associated information on clinical trials”, and “About clinical trials”.