A pilot test of a full-text, medical literature retrieval service demonstrated its capabilities for on-line search and retrieval of references, abstracts, and/or full-text journal articles. During a three-month test period, more than 500 health care professionals conducted 9,377 searches using computer terminals located in seven different health care sites. Searches were initiated for purposes of patient care, medical education, research, or for browsing. The majority of responders to a questionnaire given during the test period said they would continue to use the service during the pilot test, and only about 1% reported the search process difficult to use or not "user-friendly." It is predictable that with a comprehensive data base, full-text medical literature retrieval can be very useful for medical practice, medical education, and research.