A service excellence system for ambulatory care pharmacy services is described. An interview was designed to measure the needs, expectations, and priorities of a random sample of ambulatory care patients at a 964-bed county teaching hospital and its clinics to determine trends in patient service and satisfaction. The interviews were conducted by the same interviewers with the same script, and follow-up was continuous for two years. Information was summarized for each question and pharmacy site. In defining "service excellence" from a patient's perspective, it was determined that patients wanted a continuation of low-cost prescriptions, decreased waiting time, a friendlier, more caring staff, and environmental modifications. A service excellence system with key performance indicators was then designed and implemented. This effort included recruiting employees with behaviors that support service excellence, training employees to deliver service excellence, creating an environment that promotes patient satisfaction, and designing an ongoing monitoring system. Next, it was imperative to change the attitudes of staff and existing processes to meet or exceed patients' expectations. This phase addressed such issues as patient waiting time, staff-patient interaction, patients' environmental concerns, and staff ideas for service improvement. Finally, changes in service levels were measured. Overall patient satisfaction increased from 72% to 93% at the maincampus pharmacies. Satisfaction at the smaller sites rose from 85% to 95%, while turnaround time and number of pharmacist full-time-equivalents remained stable. A service excellence program was effective in addressing the service issues of ambulatory care patients at a large teaching hospital.