A disease registry is an organized system that collects standardized data on a population with a particular disease. It includes demographics, diagnoses, treatments, and follow-ups. Registries can range from paper files kept by an individual doctor to complex online databases accessed across institutions. They provide quality goals and reminders to healthcare providers. Registries have clinical, technical, and analytical components and ensure confidentiality and privacy in data collection, management, and reporting. The quality of data in a registry determines its utility for research and improving healthcare processes.