The aim of this project was to improve the effects of patient-controlled analgesia (PCA) for patients after orthopedic surgery. During data collection, several problems were identified including that patients did not understand how to use PCA after surgery, resulting in a low 48% of patient satisfaction. Moreover, with only 44% nurses familiar with PCA, they could not solve PCA problems immediately. Lack of educational pamphlets, machine errors, and managerial procedures were also identified as problems in this project. Therefore, an improvement team was formed to solve problems. After completing documentation forms, machine manuals, establishing error management standards and standard project procedures, and holding continuing education for nurses, patient understanding of PCA improved from 48% to 92%. Nurses' familiarity with PCA also increased from 44% to 100%. Implementation of this project not only significantly reduced patients' pain after surgery, but also shortened the time for dealing with errors related to PCA use. Finally, patient satisfaction and quality of nursing care were improved.