The development of a comprehensive model of pharmacy practice in an ambulatory care setting is described. From 1991 to 1994, the department of ambulatory care pharmacy services at The University of Illinois at Chicago Medical Center converted its main outpatient pharmacy into a Pharmaceutical Care Center to serve as a model for community and hospital-based ambulatory care pharmacy services. The Pharmaceutical Care Center includes a waiting area, five private patient-assessment rooms, an examination room, a place for reviewing patient profiles and reference materials, space for storage and automation, an i.v. admixture area, a conference room, and office space. It serves 120-150 patients per day (10% just discharged from the hospital, 90% seen in the clinic system). Pharmacy clerkship students and residents, under the oversight of faculty, conduct patient assessments, educate patients and family, monitor outcomes, and intervene when drug-related problems are detected. Patient assessments and therapeutic interventions are documented in the patient's medical record. Computers, automated medication filling, and technical support are used to enable pharmacists to concentrate on patient care. A model ambulatory care pharmacy provides both drug distribution and direct patient care services.