Customer service initiatives in healthcare have become a popular way of attempting to improve patient satisfaction. This study investigates the effect of clinically focused customer service training on patient satisfaction in the setting of a 62,000-visit emergency department and level I trauma center. Analysis of patient complaints, patient compliments, and a statistically verified patient-satisfaction survey indicate that (1) all 14 key quality characteristics identified in the survey increased dramatically in the study period; (2) patient complaints decreased by over 70 percent from 2.6 per 1,000 emergency department (ED) visits to 0.6 per 1,000 ED visits following customer service training; and (3) patient compliments increased more than 100 percent from 1.1 per 1,000 ED visits to 2.3 per 1,000 ED visits. The most dramatic improvement in the patient satisfaction survey came in ratings of skill of the emergency physician, likelihood of returning, skill of the emergency department nurse, and overall satisfaction. These results show that clinically focused customer service training improves patient satisfaction and ratings of physician and nurse skill. They also suggest that such training may offer a substantial competitive market advantage, as well as improve the patients' perception of quality and outcome.