Drug information centers have existed for more than 20 years. Well over 100 centers function across the country, primarily affiliated with hospitals and/or colleges of pharmacy. The centers serve an audience of primarily health professionals but in some settings meet consumer needs. Three general areas of responsibility exist: service, education and research. In the area of service, specific functions such as answering questions, supporting the Pharmacy and Therapeutics Committee, and preparing newsletters are frequent. Educational responsibilities often include teaching pharmacy students drug information skills. Evaluation of the services has focused mostly on answering questions and Pharmacy and Therapeutics (P&T) Committee functions. Commercial information systems used by Drug Information Centers (DICs) are increasingly sophisticated and offer the opportunity to improve efficiency. Funding generally is provided by the institution with which the center is affiliated. Attempts to charge for services have provided only modest revenue. Drug information centers continue to mature and offer a useful service.