Understanding the important aspects of measuring outcomes will prepare pharmacists for changes in the marketplace and help them to assess the results of studies that will appear in subsequent issues of the Journal of the American Pharmaceutical Association and the research journals of other health services professions. In any evaluation of quality, all three quality measures (structure, process, and outcomes) must be considered. No one measure, in isolation, can describe the quality of care provided. Thus, the best patient care will come from health care practitioners who document structure, process, and outcomes and who evaluate these measures to provide appropriate care. The pharmacist cannot dispense prescriptions or provide pharmaceutical care without a pharmacy, drug inventory, or patient profiles, all of which are important structural inputs. The pharmacist takes a medication history, monitors the drug regimen, and counsels the patient on the appropriate way to use the treatment, all vital process activities. The objective of these inputs and actions is to improve the health status of the patient. Outcomes, therefore, are the intended endpoints of care, and occasional unintended effects (e.g., adverse drug reactions) as well. The future of pharmacy rests on demonstrating the positive effect of pharmaceutical care on patient outcomes. Pharmacists have always been part of the system of checks and balances in health care delivery. As the provision of health services changes, opportunities to assess the process and structure of care and to document patient outcomes will increase. Pharmacists are well positioned to intervene in patient care, but if they do not demonstrate the value of pharmacy services, they will face competition from alternative providers. Some have even suggested less expensive alternatives to having pharmacists dispense medications. Pharmacists must establish that their role goes beyond dispensing to include cognitive services such as compliance programs, screening services, glucose monitoring, and disease management programs. Pharmacists must document their role and its effects on patient outcomes.