Disease management has become an increasingly popular tool used to manage people with chronic diseases in managed care organizations. The implementation of these programs, coupled with pressures to document quality and control costs, has increased the need for information regarding the health services provided to patients. This paper gives an overview of selected topics involved in data collection, including medical record review, databases, automated systems, and disease management software. The preliminary uses of the Internet and wireless technology are also discussed. Efficient data collection requires the identification of pertinent information from clinical, patient-reported, and economic data. Several sources provide this. The medical record is considered the gold standard for providing clinical information. However, collecting this data can be time consuming and expensive. Claims that databases have gained popularity for their comprehensiveness and accessibility are eroded by the lack of detailed clinical information. Direct communication with patients via telephone is commonly used in disease management programs, but its effectiveness as a data collection tool is not well documented. The use of the Internet and wireless technology in data collection is an exciting opportunity, since it provides interactive access between providers, patients, and the managed care organization. In most cases, a combination of data sources will be required to collect all the necessary information. However, claims databases, medical chart review, and telephone interviews are the backbone of data collection in disease management. The computerization of medical information systems, and use of the Internet and wireless technologies, should facilitate future data collection.