National Clinical Database (NCD) is a multidisciplinary clinical registry platform collecting patient case information throughout Japan in close linkage with the board certification systems for various Japanese professional medical societies. Since its initiation of data collection in 2011, NCD has grown in its size as more national level professional societies joined its activity. Its current case registration volume is above 150 million cases per year. In this commentary, we will introduce four patterns of utilization examples of NCD: 1) data use for the assessment and improvement of healthcare quality in Japan, 2) data use for conducting observational studies to answer physician generated clinical questions, 3) data use for health services research, and 4) Use of the registry platform for industry-government-academia collaboration. We will also go over some of the data quality management and improvement activities at NCD, which they regard as one of the top priority issues in the operation of the institution. These include: defining and designing of the data elements, administrative support from the office staffs, data error checking using the web based registration system, and data audit and validation.