Introduction: Chronic pain is a significant clinical problem in the world. No treatment is quite effective for chronic pain due to its complex nature. However timely retrieval of accurate and comprehensive information through organized clinical and epidemiological studies is an essential prerequisite for providing high-quality clinical care and more accurate health care planning. This can be achieved by the creation of an electronic registry system as a strong source of information. The purpose of this study was to develop and evaluate a chronic pain registry for patients with chronic pain syndromes.Material and Methods: In the current study, Onion architecture with the MVC design pattern was selected in design phase. Using onion architecture leads to more flexible and reusable codes and results in easier development and maintenance. In the development phase, MYSQL DBMS and the PHP programming language, which are suitable for developing the web-based system, were used.Results: The minimum data set was determined in the previous study. This dataset covered six areas: demographic information, initial pain assessment, medical history, mental health and well-being, diagnostic measures, and diagnosis and treatment plan. A web-based pain registry system was developed based on the minimum data set.Conclusion: There are many studies for development of web- based pain registries in the world but there is a few information about technical architecture and structure in design phase. In current study, we focused on the technical architecture design of system. Using onion architecture leads to more flexible and reusable codes and results in easier development and maintenance. In the current study, it was chosen to use MYSQL and the PHP programming language, which is suitable for developing the web-based system. Finally, a web-based registry system was developed to store and report on the information of patients suffering from chronic pain. It can manage and control chronic pain and facilitate future research.